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Sample records for strongly implicit procedure

  1. Combined incomplete LU and strongly implicit procedure preconditioning

    SciTech Connect

    Meese, E.A.

    1996-12-31

    For the solution of large sparse linear systems of equations, the Krylov-subspace methods have gained great merit. Their efficiency are, however, largely dependent upon preconditioning of the equation-system. A family of matrix factorisations often used for preconditioning, is obtained from a truncated Gaussian elimination, ILU(p). Less common, supposedly due to it`s restriction to certain sparsity patterns, is factorisations generated by the strongly implicit procedure (SIP). The ideas from ILU(p) and SIP are used in this paper to construct a generalized strongly implicit procedure, applicable to matrices with any sparsity pattern. The new algorithm has been run on some test equations, and efficiency improvements over ILU(p) was found.

  2. Transient, compressible heat and mass transfer in porous media using the strongly implicit iteration procedure.

    NASA Technical Reports Server (NTRS)

    Curry, D. M.; Cox, J. E.

    1972-01-01

    Coupled nonlinear partial differential equations describing heat and mass transfer in a porous matrix are solved in finite difference form with the aid of a new iterative technique (the strongly implicit procedure). Example numerical results demonstrate the characteristics of heat and mass transport in a porous matrix such as a charring ablator. It is emphasized that multidimensional flow must be considered when predicting the thermal response of a porous material subjected to nonuniform boundary conditions.

  3. Two-demensional analysis of heat and mass transfer in porous media using the strongly implicit procedure

    NASA Technical Reports Server (NTRS)

    Curry, D. M.

    1974-01-01

    Numerical results of the heat and mass transfer in a porous matrix are presented. The coupled, nonlinear partial differential equations describing this physical phenomenon are solved in finite difference form for two dimensions, using a new iterative technique (the strongly implicit procedure). The influence of the external environment conditions (heating and pressure) is shown to produce two-dimensional flow in the porous matrix. Typical fluid and solid temperature distributions in the porous matrix and internal pressure distributions are presented.

  4. Equivalent Stimuli Are More Strongly Related after Training with Delayed Matching than after Simultaneous Matching: A Study Using the Implicit Relational Assessment Procedure (IRAP)

    ERIC Educational Resources Information Center

    Bortoloti, Renato; de Rose, Julio C.

    2012-01-01

    Bortoloti and de Rose (2009) found evidence that the level of functional transfer is higher in equivalence classes generated by delayed matching to sample (DMTS) than in classes generated by simultaneous matching (SMTS). We attempted to replicate these findings with the Implicit Relational Assessment Procedure (IRAP). Two experimental groups…

  5. Examining the Implicit Relational Assessment Procedure: Four Preliminary Studies

    ERIC Educational Resources Information Center

    Drake, Chad E.; Kellum, Karen Kate; Wilson, Kelly G.; Luoma, Jason B.; Weinstein, Jonathan H.; Adams, Catherine H.

    2010-01-01

    The Implicit Relational Assessment Procedure (IRAP) is a relatively new measure of implicit cognition that tests cognition as relational behavior instead of an associative activity and thus may provide a more specific measure of cognitive repertoires, including those for social biases, than better known implicit measures such as the Implicit…

  6. Measuring implicit attitudes: A positive framing bias flaw in the Implicit Relational Assessment Procedure (IRAP).

    PubMed

    O'Shea, Brian; Watson, Derrick G; Brown, Gordon D A

    2016-02-01

    How can implicit attitudes best be measured? The Implicit Relational Assessment Procedure (IRAP), unlike the Implicit Association Test (IAT), claims to measure absolute, not just relative, implicit attitudes. In the IRAP, participants make congruent (Fat Person-Active: false; Fat Person-Unhealthy: true) or incongruent (Fat Person-Active: true; Fat Person-Unhealthy: false) responses in different blocks of trials. IRAP experiments have reported positive or neutral implicit attitudes (e.g., neutral attitudes toward fat people) in cases in which negative attitudes are normally found on explicit or other implicit measures. It was hypothesized that these results might reflect a positive framing bias (PFB) that occurs when participants complete the IRAP. Implicit attitudes toward categories with varying prior associations (nonwords, social systems, flowers and insects, thin and fat people) were measured. Three conditions (standard, positive framing, and negative framing) were used to measure whether framing influenced estimates of implicit attitudes. It was found that IRAP scores were influenced by how the task was framed to the participants, that the framing effect was modulated by the strength of prior stimulus associations, and that a default PFB led to an overestimation of positive implicit attitudes when measured by the IRAP. Overall, the findings question the validity of the IRAP as a tool for the measurement of absolute implicit attitudes. A new tool (Simple Implicit Procedure:SIP) for measuring absolute, not just relative, implicit attitudes is proposed. (PsycINFO Database Record PMID:26075407

  7. Implicit Procedural Learning in Fragile X and Down Syndrome

    ERIC Educational Resources Information Center

    Bussy, G.; Charrin, E.; Brun, A.; Curie, A.; des Portes, V.

    2011-01-01

    Background: Procedural learning refers to rule-based motor skill learning and storage. It involves the cerebellum, striatum and motor areas of the frontal lobe network. Fragile X syndrome, which has been linked with anatomical abnormalities within the striatum, may result in implicit procedural learning deficit. Methods: To address this issue, a…

  8. On the Formation and Persistence of Implicit Attitudes: New Evidence from the Implicit Relational Assessment Procedure (IRAP)

    ERIC Educational Resources Information Center

    Hughes, Sean; Barnes-Holmes, Dermot

    2011-01-01

    Research increasingly supports the Implicit Relational Assessment Procedure (IRAP) as a measure capable of providing a sensitive index of preexisting implicit attitudes and cognitions. The current study constitutes the first attempt to determine if the IRAP is also sensitive to implicit attitudes engineered through either direct relational…

  9. Assessing Children's Implicit Attitudes Using the Affect Misattribution Procedure

    ERIC Educational Resources Information Center

    Williams, Amanda; Steele, Jennifer R.; Lipman, Corey

    2016-01-01

    In the current research, we examined whether the Affect Misattribution Procedure (AMP) could be successfully adapted as an implicit measure of children's attitudes. We tested this possibility in 3 studies with 5- to 10-year-old children. In Study 1, we found evidence that children misattribute affect elicited by attitudinally positive (e.g., cute…

  10. The Implicit Relational Assessment Procedure as a Measure of Implicit Depression and the Role of Psychological Flexibility

    ERIC Educational Resources Information Center

    Hussey, Ian; Barnes-Holmes, Dermot

    2012-01-01

    A broad implicit measure of depressive emotional reactions was created by mapping the content of the depression scale from the Depression Anxiety and Stress Scale (DASS) on to the Implicit Relational Assessment Procedure (IRAP). Participants were asked to relate pairings of antecedents and emotional reactions that followed the formula "When X…

  11. The Implicit Relational Assessment Procedure (IRAP) as a Measure of Spider Fear

    ERIC Educational Resources Information Center

    Nicholson, Emma; Barnes-Holmes, Dermot

    2012-01-01

    A greater understanding of implicit cognition can provide important information regarding the etiology and maintenance of psychological disorders. The current study sought to determine the utility of the Implicit Relational Assessment Procedure (IRAP) as a measure of implicit aversive bias toward spiders in two groups of known variation, high fear…

  12. Using the Implicit Association Test and the Implicit Relational Assessment Procedure to Measure Attitudes toward Meat and Vegetables in Vegetarians and Meat-Eaters

    ERIC Educational Resources Information Center

    Barnes-Holmes, Dermot; Murtagh, Louise; Barnes-Holmes, Yvonne; Stewart, Ian

    2010-01-01

    The current study aimed to assess the implicit attitudes of vegetarians and non-vegetarians towards meat and vegetables, using the Implicit Association Test (IAT) and the Implicit Relational Assessment Procedure (IRAP). Both measures involved asking participants to respond, under time pressure, to pictures of meat or vegetables as either positive…

  13. Rhythms of Dialogue and Referential Activity: Implicit Process across Procedural and Verbal Realms

    ERIC Educational Resources Information Center

    Ritter, Michael S.

    2009-01-01

    This work examines the relationship between implicit procedural and implicit verbal processes as they occur in natural adult conversation. Theoretical insights and empirical findings are rooted in a move towards integration of Bucci's "Referential Activity" (RA) and "Multiple Code" perspectives and Beebe and Jaffe's "Dyadic Systems" and "Rhythms…

  14. The Implicit Relational Assessment Procedure (IRAP) and the Malleability of Ageist Attitudes

    ERIC Educational Resources Information Center

    Cullen, Claire; Barnes-Holmes, Dermot; Barnes-Holmes, Yvonne; Stewart, Ian

    2009-01-01

    The current study examined the malleability of implicit attitudes using the Implicit Relational Assessment Procedure (IRAP). In Experiment 1, "similar" and "opposite" were presented as response options with the sample terms "old people" and "young people" and various positive and negative target stimuli. Results showed significantly faster…

  15. Creating an Implicit Measure of Cognition More Suited to Applied Research: A Test of the Mixed Trial-Implicit Relational Assessment Procedure (MT-IRAP)

    ERIC Educational Resources Information Center

    Levin, Michael E.; Hayes, Steven C.; Waltz, Thomas

    2010-01-01

    The Implicit Relational Assessment Procedure (IRAP) is a promising tool for measuring implicit cognitions in applied research. However, the need for training and block effects can limit its capacity to assess effects with individual stimuli and participants, both of which are important for applied research. We developed a modified IRAP, the Mixed…

  16. A Sketch of the Implicit Relational Assessment Procedure (IRAP) and the Relational Elaboration and Coherence (REC) Model

    ERIC Educational Resources Information Center

    Barnes-Holmes, Dermot; Barnes-Holmes, Yvonne; Stewart, Ian; Boles, Shawn

    2010-01-01

    The current article outlines a behavior-analytic approach to the study of so-called implicit attitudes and cognition. The Implicit Relational Assessment Procedure (IRAP), the conceptual basis of which was derived from relational frame theory, is offered as a methodology that may be used in the experimental analysis of implicit attitudes and…

  17. Obesity, food restriction, and implicit attitudes to healthy and unhealthy foods: Lessons learned from the implicit relational assessment procedure.

    PubMed

    McKenna, Ian; Hughes, Sean; Barnes-Holmes, Dermot; De Schryver, Maarten; Yoder, Ruth; O'Shea, Donal

    2016-05-01

    It has been argued that obese individuals evaluate high caloric, palatable foods more positively than their normal weight peers, and that this positivity bias causes them to consume such foods, even when healthy alternatives are available. Yet when self-reported and automatic food preferences are assessed no such evaluative biases tend to emerge. We argue that situational (food deprivation) and methodological factors may explain why implicit measures often fail to discriminate between the food-evaluations of these two groups. Across three studies we manipulated the food deprivation state of clinically obese and normal-weight participants and then exposed them to an indirect procedure (IRAP) and self-report questionnaires. We found that automatic food-related cognition was moderated by a person's weight status and food deprivation state. Our findings suggest that the diagnostic and predictive value of implicit measures may be increased when (a) situational moderators are taken into consideration and (b) we pay greater attention to the different ways in which people automatically relate rather than simply categorize food stimuli. PMID:26877215

  18. Implicit memory in Korsakoff's syndrome: a review of procedural learning and priming studies.

    PubMed

    Hayes, Scott M; Fortier, Catherine B; Levine, Andrea; Milberg, William P; McGlinchey, Regina

    2012-06-01

    Korsakoff's syndrome (KS) is characterized by dense anterograde amnesia resulting from damage to the diencephalon region, typically resulting from chronic alcohol abuse and thiamine deficiency. This review assesses the integrity of the implicit memory system in KS, focusing on studies of procedural learning and priming. KS patients are impaired on several measures of procedural memory, most likely due to impairment in cognitive functions associated with alcohol-related neural damage outside of the diencephalon. The pattern of performance on tasks of implicit priming suggests reliance on a residual, non-flexible memory operating more or less in an automatic fashion. Our review concludes that whether measures of implicit memory reveal intact or impaired performance in individuals with KS depends heavily on specific task parameters and demands, including timing between stimuli, the specific nature of the stimuli used in a task, and the integrity of supportive cognitive functions necessary for performance. PMID:22592661

  19. Implicit Memory in Korsakoff’s Syndrome: A Review of Procedural Learning and Priming Studies

    PubMed Central

    Hayes, Scott M.; Fortier, Catherine B.; Levine, Andrea; Milberg, William P.; McGlinchey, Regina

    2013-01-01

    Korsakoff’s syndrome (KS) is characterized by dense anterograde amnesia resulting from damage to the diencephalon region, typically resulting from chronic alcohol abuse and thiamine deficiency. This review assesses the integrity of the implicit memory system in KS, focusing on studies of procedural learning and priming. KS patients are impaired on several measures of procedural memory, most likely due to impairment in cognitive functions associated with alcohol-related neural damage outside of the diencephalon. The pattern of performance on tasks of implicit priming suggests reliance on a residual, non-flexible memory operating more or less in an automatic fashion. Our review concludes that whether measures of implicit memory reveal intact or impaired performance in individuals with KS depends heavily on specific task parameters and demands, including timing between stimuli, the specific nature of the stimuli used in a task, and the integrity of supportive cognitive functions necessary for performance. PMID:22592661

  20. The Implicit Relational Assessment Procedure as a Measure of Self-Esteem

    ERIC Educational Resources Information Center

    Timko, C. Alix; England, Erica L.; Herbert, James D.; Forman, Evan M.

    2010-01-01

    Two studies were conducted to pilot the Implicit Relational Assessment Procedure (IRAP) in measuring attitudes toward the self: one related to body image specifically and another assessing the broader construct of self-esteem. Study 1 utilized the IRAP with female college students to examine self-referential beliefs regarding body image. Results…

  1. Understanding and Using the Brief Implicit Association Test: Recommended Scoring Procedures

    PubMed Central

    Nosek, Brian A.; Bar-Anan, Yoav; Sriram, N.; Axt, Jordan; Greenwald, Anthony G.

    2014-01-01

    A brief version of the Implicit Association Test (BIAT) has been introduced. The present research identified analytical best practices for overall psychometric performance of the BIAT. In 7 studies and multiple replications, we investigated analytic practices with several evaluation criteria: sensitivity to detecting known effects and group differences, internal consistency, relations with implicit measures of the same topic, relations with explicit measures of the same topic and other criterion variables, and resistance to an extraneous influence of average response time. The data transformation algorithms D outperformed other approaches. This replicates and extends the strong prior performance of D compared to conventional analytic techniques. We conclude with recommended analytic practices for standard use of the BIAT. PMID:25485938

  2. Implicit particle methods and their connection to weak and strong 4D-Var

    NASA Astrophysics Data System (ADS)

    Morzfeld, M.; Atkins, E.; Chorin, A. J.

    2012-12-01

    The implicit particle filter is a Monte Carlo method for data assimilation. The idea is to guide the particles to remain in the high-probability regions of the posterior pdf. This is done in two steps. First, the high-probability regions are identified by a numerical minimization; second, samples within the high-probability regions are obtained by solving algebraic equations with a random right-hand-side. Specifically, the implicit particle filter finds the mode of the posterior pdf and then solves algebraic equations to obtain samples in the neighborhood of this mode. In variational data assimilation, one finds the mode of the posterior pdf. There is thus a connection between the implicit particle filter and variational data assimilation. In particular, one can turn variational codes into implicit particle filters by adding a sampling step (i.e. solving simple algebraic equations). The benefit can be that the implicit filter improves the state estimate by approximating the conditional mean, which is the minimum mean square error estimate. We present an example in detail to explain the implicit particle filter in its variational implementation.

  3. An Implicit Finite Difference Solution to the Viscous Radiating Shock Layer with Strong Blowing. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Garrett, L. B.

    1971-01-01

    An implicit finite difference scheme is developed for the fully coupled solution of the viscous radiating stagnation line equations, including strong blowing. Solutions are presented for both air injection and carbon phenolic ablation products injection into air at conditions near the peak radiative heating point in an earth entry trajectory from interplanetary return missions. A detailed radiative transport code that accounts for the important radiative exchange processes for gaseous mixtures in local thermodynamic and chemical equilibrium is utilized.

  4. The Role of Mental Imagery in Depression: Negative Mental Imagery Induces Strong Implicit and Explicit Affect in Depression.

    PubMed

    Görgen, Stefanie Maria; Joormann, Jutta; Hiller, Wolfgang; Witthöft, Michael

    2015-01-01

    Mental imagery, seeing with the mind's eyes, can induce stronger positive as well as negative affect compared to verbal processing. Given this emotion-amplifying effect, it appears likely that mental images play an important role in affective disorders. According to the subcomponents model of depression, depressed mood is maintained by both negative imagery (which amplifies negative mood) and less efficient positive imagery processes. Empirical research on the link between mental imagery and affect in clinical depression, however, is still sparse. This study aimed at testing the role of mental imagery in depression, using a modified version of the affect misattribution procedure (AMP) and the self-assessment manikin (SAM) to assess implicit (AMP) and explicit (SAM) affect elicited by mental images, pictures, and verbal processing in clinically depressed participants (n = 32) compared to healthy controls (n = 32). In individuals with a depressive disorder, compared to healthy controls, negative mental images induced stronger negative affect in the explicit as well as implicit measure. Negative mental imagery did not, however, elicit greater increases in explicitly and implicitly assessed negative affect compared to other processing modalities (verbal processing, pictures) in the depressed group. Additionally, a positive imagery deficit in depression was observed in the explicit measure. Interestingly, the two groups did not differ in implicitly assessed affect after positive imagery, indicating that depressed individuals might benefit from positive imagery on an implicit or automatic level. Overall, our findings suggest that mental imagery also plays an important role in depression and confirm the potential of novel treatment approaches for depression, such as the promotion of positive imagery. PMID:26217240

  5. The Role of Mental Imagery in Depression: Negative Mental Imagery Induces Strong Implicit and Explicit Affect in Depression

    PubMed Central

    Görgen, Stefanie Maria; Joormann, Jutta; Hiller, Wolfgang; Witthöft, Michael

    2015-01-01

    Mental imagery, seeing with the mind’s eyes, can induce stronger positive as well as negative affect compared to verbal processing. Given this emotion-amplifying effect, it appears likely that mental images play an important role in affective disorders. According to the subcomponents model of depression, depressed mood is maintained by both negative imagery (which amplifies negative mood) and less efficient positive imagery processes. Empirical research on the link between mental imagery and affect in clinical depression, however, is still sparse. This study aimed at testing the role of mental imagery in depression, using a modified version of the affect misattribution procedure (AMP) and the self-assessment manikin (SAM) to assess implicit (AMP) and explicit (SAM) affect elicited by mental images, pictures, and verbal processing in clinically depressed participants (n = 32) compared to healthy controls (n = 32). In individuals with a depressive disorder, compared to healthy controls, negative mental images induced stronger negative affect in the explicit as well as implicit measure. Negative mental imagery did not, however, elicit greater increases in explicitly and implicitly assessed negative affect compared to other processing modalities (verbal processing, pictures) in the depressed group. Additionally, a positive imagery deficit in depression was observed in the explicit measure. Interestingly, the two groups did not differ in implicitly assessed affect after positive imagery, indicating that depressed individuals might benefit from positive imagery on an implicit or automatic level. Overall, our findings suggest that mental imagery also plays an important role in depression and confirm the potential of novel treatment approaches for depression, such as the promotion of positive imagery. PMID:26217240

  6. Quality control by <strong>HyperS>pectral <strong>I>maging (HSI) in solid waste recycling: logics, algorithms and procedures

    NASA Astrophysics Data System (ADS)

    Bonifazi, Giuseppe; Serranti, Silvia

    2014-03-01

    In secondary raw materials and recycling sectors, the products quality represents, more and more, the key issue to pursuit in order to be competitive in a more and more demanding market, where quality standards and products certification play a preheminent role. These goals assume particular importance when recycling actions are applied. Recovered products, resulting from waste materials, and/or dismissed products processing, are, in fact, always seen with a certain suspect. An adequate response of the industry to the market can only be given through the utilization of equipment and procedures ensuring pure, high-quality production, and efficient work and cost. All these goals can be reached adopting not only more efficient equipment and layouts, but also introducing new processing logics able to realize a full control of the handled material flow streams fulfilling, at the same time, i) an easy management of the procedures, ii) an efficient use of the energy, iii) the definition and set up of reliable and robust procedures, iv) the possibility to implement network connectivity capabilities finalized to a remote monitoring and control of the processes and v) a full data storage, analysis and retrieving. Furthermore the ongoing legislation and regulation require the implementation of recycling infrastructure characterised by high resources efficiency and low environmental impacts, both aspects being strongly linked to the waste materials and/or dismissed products original characteristics. For these reasons an optimal recycling infrastructure design primarily requires a full knowledge of the characteristics of the input waste. What previously outlined requires the introduction of a new important concept to apply in solid waste recycling, the recycling-oriented characterization, that is the set of actions addressed to strategically determine selected attributes, in order to get goaloriented data on waste for the development, implementation or improvement of recycling

  7. The Neural Correlates of Implicit and Explicit Sequence Learning: Interacting Networks Revealed by the Process Dissociation Procedure

    ERIC Educational Resources Information Center

    Laureys, Steven; Degueldre, Christian; Del Fiore, Guy; Aerts, Joel; Luxen, Andre; Van Der Linden, Martial; Cleeremans, Axel; Maquet, Pierre; Destrebecqz, Arnaud; Peigneux, Philippe

    2005-01-01

    In two H[subscript 2] [superscript 15]O PET scan experiments, we investigated the cerebral correlates of explicit and implicit knowledge in a serial reaction time (SRT) task. To do so, we used a novel application of the Process Dissociation Procedure, a behavioral paradigm that makes it possible to separately assess conscious and unconscious…

  8. The Joint Painting Procedure to Assess Implicit Aspects of the Mother-Child Relationship in Middle Childhood

    ERIC Educational Resources Information Center

    Gavron, Tami; Mayseless, Ofra

    2015-01-01

    This brief report describes a preliminary study that examined the association between implicit aspects of parent-child relationships as assessed by the Joint Painting Procedure (JPP) and self-report measures of the quality of mother-child relations and children's adjustment at home and at school as reported by the mothers. Forty mother-child dyads…

  9. Elicited Imitation: Toward Valid Procedures to Measure Implicit Second Language Grammatical Knowledge

    ERIC Educational Resources Information Center

    Tomita, Yasuyo; Suzuki, Wataru; Jessop, Lorena

    2009-01-01

    In second language acquisition (SLA) research, two types of second language (L2) knowledge, explicit and implicit, have been discussed for almost three decades. Although many SLA researchers agree that L2 instruction should give priority to implicit knowledge, researchers have not agreed on what type of test (e.g., oral narrative test and timed…

  10. The neural correlates of implicit and explicit sequence learning: Interacting networks revealed by the process dissociation procedure

    PubMed Central

    Destrebecqz, Arnaud; Peigneux, Philippe; Laureys, Steven; Degueldre, Christian; Del Fiore, Guy; Aerts, Joël; Luxen, André; Van Der Linden, Martial; Cleeremans, Axel; Maquet, Pierre

    2005-01-01

    In two H215O PET scan experiments, we investigated the cerebral correlates of explicit and implicit knowledge in a serial reaction time (SRT) task. To do so, we used a novel application of the Process Dissociation Procedure, a behavioral paradigm that makes it possible to separately assess conscious and unconscious contributions to performance during a subsequent sequence generation task. To manipulate the extent to which the repeating sequential pattern was learned explicitly, we varied the pace of the choice reaction time task—a variable that is known to have differential effects on the extent to which sensitivity to sequence structure involves implicit or explicit knowledge. Results showed that activity in the striatum subtends the implicit component of performance during recollection of a learned sequence, whereas the anterior cingulate/mesial prefrontal cortex (ACC/MPFC) supports the explicit component. Most importantly, we found that the ACC/MPFC exerts control on the activity of the striatum during retrieval of the sequence after explicit learning, whereas the activity of these regions is uncoupled when learning had been essentially implicit. These data suggest that implicit learning processes can be successfully controlled by conscious knowledge when learning is essentially explicit. They also supply further evidence for a partial dissociation between the neural substrates supporting conscious and nonconscious components of performance during recollection of a learned sequence. PMID:16166397

  11. On a fourth order accurate implicit finite difference scheme for hyperbolic conservation laws. I - Nonstiff strongly dynamic problems

    NASA Technical Reports Server (NTRS)

    Harten, A.; Tal-Ezer, H.

    1981-01-01

    An implicit finite difference method of fourth order accuracy in space and time is introduced for the numerical solution of one-dimensional systems of hyperbolic conservation laws. The basic form of the method is a two-level scheme which is unconditionally stable and nondissipative. The scheme uses only three mesh points at level t and three mesh points at level t + delta t. The dissipative version of the basic method given is conditionally stable under the CFL (Courant-Friedrichs-Lewy) condition. This version is particularly useful for the numerical solution of problems with strong but nonstiff dynamic features, where the CFL restriction is reasonable on accuracy grounds. Numerical results are provided to illustrate properties of the proposed method.

  12. Three-dimensional viscous-flow computations using a directionally hybrid implicit-explicit procedure

    NASA Astrophysics Data System (ADS)

    Rizk, Y. M.; Chaussee, D. S.

    A new, directionally dependent, hybrid numerical algorithm for solving the unsteady, three-dimensional Navier-Stokes equations has been developed and used to compute the viscous supersonic flow over complex configurations, which may generate local regions of embedded subsonic or streamwise separated flows or both. The new hybrid implicit-explicit algorithm is derived from the more general implicit Beam-Warming algorithm and is particularly suitable for viscous computations in which the grid spacing in the direction outward from the body is considerably smaller than the spacing in the other two directions. Numerical results obtained from both the hybrid and implicit schemes are presented and compared on the basis of numerical stability, convergence history, and computer and core memory requirements.

  13. An implicit finite-difference solution to the viscous shock layer, including the effects of radiation and strong blowing

    NASA Technical Reports Server (NTRS)

    Garrett, L. B.; Smith, G. L.; Perkins, J. N.

    1972-01-01

    An implicit finite-difference scheme is developed for the fully coupled solution of the viscous, radiating stagnation-streamline equations, including strong blowing. Solutions are presented for both air injection and injection of carbon-phenolic ablation products into air at conditions near the peak radiative heating point in an earth entry trajectory from interplanetary return missions. A detailed radiative-transport code that accounts for the important radiative exchange processes for gaseous mixtures in local thermodynamic and chemical equilibrium is utilized in the study. With minimum number of assumptions for the initially unknown parameters and profile distributions, convergent solutions to the full stagnation-line equations are rapidly obtained by a method of successive approximations. Damping of selected profiles is required to aid convergence of the solutions for massive blowing. It is shown that certain finite-difference approximations to the governing differential equations stabilize and improve the solutions. Detailed comparisons are made with the numerical results of previous investigations. Results of the present study indicate lower radiative heat fluxes at the wall for carbonphenolic ablation than previously predicted.

  14. An implicit velocity decoupling procedure for the incompressible Navier-Stokes equations

    NASA Astrophysics Data System (ADS)

    Kim, Kyoungyoun; Baek, Seung-Jin; Sung, Hyung Jin

    2002-01-01

    An efficient numerical method to solve the unsteady incompressible Navier-Stokes equations is developed. A fully implicit time advancement is employed to avoid the Courant-Friedrichs-Lewy restriction, where the Crank-Nicolson discretization is used for both the diffusion and convection terms. Based on a block LU decomposition, velocity-pressure decoupling is achieved in conjunction with the approximate factorization. The main emphasis is placed on the additional decoupling of the intermediate velocity components with only nth time step velocity. The temporal second-order accuracy is preserved with the approximate factorization without any modification of boundary conditions. Since the decoupled momentum equations are solved without iteration, the computational time is reduced significantly. The present decoupling method is validated by solving several test cases, in particular, the turbulent minimal channel flow unit. Copyright

  15. The Implicit Relational Assessment Procedure (IRAP) as a Response-Time and Event-Related-Potentials Methodology for Testing Natural Verbal Relations: A Preliminary Study

    ERIC Educational Resources Information Center

    Barnes-Holmes, Dermot; Hayden, Eilish; Barnes-Holmes, Yvonne; Stewart, Ian

    2008-01-01

    The current article reports the first attempt to test the Implicit Relational Assessment Procedure (IRAP), as a group-based measure of natural verbal relations, using both response-latency and event-related potentials as dependent variables. On each trial of the IRAP, participants were presented with 1 of 2 attribute stimuli ("Pleasant" or…

  16. Indirect Measurement of Sexual Orientation: Comparison of the Implicit Relational Assessment Procedure, Viewing Time, and Choice Reaction Time Tasks.

    PubMed

    Rönspies, Jelena; Schmidt, Alexander F; Melnikova, Anna; Krumova, Rosina; Zolfagari, Asadeh; Banse, Rainer

    2015-07-01

    The present study was conducted to validate an adaptation of the Implicit Relational Assessment Procedure (IRAP) as an indirect latency-based measure of sexual orientation. Furthermore, reliability and criterion validity of the IRAP were compared to two established indirect measures of sexual orientation: a Choice Reaction Time task (CRT) and a Viewing Time (VT) task. A sample of 87 heterosexual and 35 gay men completed all three indirect measures in an online study. The IRAP and the VT predicted sexual orientation nearly perfectly. Both measures also showed a considerable amount of convergent validity. Reliabilities (internal consistencies) reached satisfactory levels. In contrast, the CRT did not tap into sexual orientation in the present study. In sum, the VT measure performed best, with the IRAP showing only slightly lower reliability and criterion validity, whereas the CRT did not yield any evidence of reliability or criterion validity in the present research. The results were discussed in the light of specific task properties of the indirect latency-based measures (task-relevance vs. task-irrelevance). PMID:25690445

  17. Implicit CAPTCHAs

    NASA Astrophysics Data System (ADS)

    Baird, Henry S.; Bentley, Jon L.

    2004-12-01

    We propose a design methodology for "implicit" CAPTCHAs to relieve drawbacks of present technology. CAPTCHAs are tests administered automatically over networks that can distinguish between people and machines and thus protect web services from abuse by programs masquerading as human users. All existing CAPTCHAs' challenges require a significant conscious effort by the person answering them -- e.g. reading and typing a nonsense word -- whereas implicit CAPTCHAs may require as little as a single click. Many CAPTCHAs distract and interrupt users, since the challenge is perceived as an irrelevant intrusion; implicit CAPTCHAs can be woven into the expected sequence of browsing using cues tailored to the site. Most existing CAPTCHAs are vulnerable to "farming-out" attacks in which challenges are passed to a networked community of human readers; by contrast, implicit CAPTCHAs are not "fungible" (in the sense of easily answerable in isolation) since they are meaningful only in the specific context of the website that is protected. Many existing CAPTCHAs irritate or threaten users since they are obviously tests of skill: implicit CAPTCHAs appear to be elementary and inevitable acts of browsing. It can often be difficult to detect when CAPTCHAs are under attack: implicit CAPTCHAs can be designed so that certain failure modes are correlated with failed bot attacks. We illustrate these design principles with examples.

  18. Implicit CAPTCHAs

    NASA Astrophysics Data System (ADS)

    Baird, Henry S.; Bentley, Jon L.

    2005-01-01

    We propose a design methodology for "implicit" CAPTCHAs to relieve drawbacks of present technology. CAPTCHAs are tests administered automatically over networks that can distinguish between people and machines and thus protect web services from abuse by programs masquerading as human users. All existing CAPTCHAs' challenges require a significant conscious effort by the person answering them -- e.g. reading and typing a nonsense word -- whereas implicit CAPTCHAs may require as little as a single click. Many CAPTCHAs distract and interrupt users, since the challenge is perceived as an irrelevant intrusion; implicit CAPTCHAs can be woven into the expected sequence of browsing using cues tailored to the site. Most existing CAPTCHAs are vulnerable to "farming-out" attacks in which challenges are passed to a networked community of human readers; by contrast, implicit CAPTCHAs are not "fungible" (in the sense of easily answerable in isolation) since they are meaningful only in the specific context of the website that is protected. Many existing CAPTCHAs irritate or threaten users since they are obviously tests of skill: implicit CAPTCHAs appear to be elementary and inevitable acts of browsing. It can often be difficult to detect when CAPTCHAs are under attack: implicit CAPTCHAs can be designed so that certain failure modes are correlated with failed bot attacks. We illustrate these design principles with examples.

  19. A RANS/DES Numerical Procedure for Axisymmetric Flows with and without Strong Rotation

    SciTech Connect

    Andrade, A J

    2007-10-30

    A RANS/DES numerical procedure with an extended Lax-Wendroff control-volume scheme and turbulence model is described for the accurate simulation of internal/external axisymmetric flow with and without strong rotation. This new procedure is an extension, from Cartesian to cylindrical coordinates, of (1) a second order accurate multi-grid, control-volume integration scheme, and (2) a k-{omega} turbulence model. This paper outlines both the axisymmetric corrections to the mentioned numerical schemes and the developments of techniques pertaining to numerical dissipation, multi-block connectivity, parallelization, etc. Furthermore, analytical and experimental case studies are presented to demonstrate accuracy and computational efficiency. Notes are also made toward numerical stability of highly rotational flows.

  20. A procedure for the extraction of airglow features in the presence of strong background radiation

    NASA Astrophysics Data System (ADS)

    Swift, W. R.; Torr, D. G.; Hamilton, C.; Dougani, H.; Torr, M. R.

    1990-09-01

    A technique is developed that can be used to derive the total intensity of band emissions from twilight airglow measurements when the basic spectral signature of the band to be considered is known. The method is designed to automatically extract total band or line intensities of a signal imbedded in background radiation several orders of magnitude greater in brightness. It is shown that the technique developed can reliably measure the intensity of both weak and strong band and line emissions in the presence of strong twilight background radiation. The method of extraction is shown as part of a general purpose spectral analysis program written in VAX FORTRAN. This extraction procedure has been used successfully on emissions of Fel, Ca(+), N2(+) (1N) (0-0) and (0-1), OH in the near UV. OI red (630nm) and green (558nm) lines in the visible, and the OH Meinel bands and O(+) (2P) 732 nm in the near IR.

  1. The Neuropharmacology of Implicit Learning

    PubMed Central

    Uddén, Julia; Folia, Vasiliki; Petersson, Karl Magnus

    2010-01-01

    Two decades of pharmacologic research on the human capacity to implicitly acquire knowledge as well as cognitive skills and procedures have yielded surprisingly few conclusive insights. We review the empirical literature of the neuropharmacology of implicit learning. We evaluate the findings in the context of relevant computational models related to neurotransmittors such as dopamine, serotonin, acetylcholine and noradrenalin. These include models for reinforcement learning, sequence production, and categorization. We conclude, based on the reviewed literature, that one can predict improved implicit acquisition by moderately elevated dopamine levels and impaired implicit acquisition by moderately decreased dopamine levels. These effects are most prominent in the dorsal striatum. This is supported by a range of behavioral tasks in the empirical literature. Similar predictions can be made for serotonin, although there is yet a lack of support in the literature for serotonin involvement in classical implicit learning tasks. There is currently a lack of evidence for a role of the noradrenergic and cholinergic systems in implicit and related forms of learning. GABA modulators, including benzodiazepines, seem to affect implicit learning in a complex manner and further research is needed. Finally, we identify allosteric AMPA receptors modulators as a potentially interesting target for future investigation of the neuropharmacology of procedural and implicit learning. PMID:21629444

  2. Final report on repair procedure of strong ground motion data from underground nuclear tests

    SciTech Connect

    Tunnell, T.W.

    1995-04-01

    Certain difficulties arise when recording close-in around motion from underground nuclear explosions. Data quality can be compromised by a variety of factors, including electromagnetic pulse, noise spikes, direct current effect, and gauge clipping and gauge tilt. From March 1988 through September 1994, EG&G Energy Measurements repaired strong round-motion data (acceleration data) from underground nuclear tests for the Los Alamos National Laboratory using, an automated repair procedure. The automated repair determined and implemented the required repairs based on user input and a consistent set of criteria. A log was kept of each repair so that the repair procedure could be duplicated. This relaxed the requirement to save the repaired data. Developed for the VAX system, the procedure allowed the user to stack up a large number of repairs, plot the repaired data, and obtain hard copies. The plotted data could then be reviewed for a given test to determine the consistency of repair for a given underground test. This feature released the user to perform other tasks while the data were being repaired.

  3. Semi-implicit and fully implicit shock-capturing methods for hyperbolic conservation laws with stiff source terms

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Shinn, J. L.

    1986-01-01

    Some numerical aspects of finite-difference algorithms for nonlinear multidimensional hyperbolic conservation laws with stiff nonhomogenous (source) terms are discussed. If the stiffness is entirely dominated by the source term, a semi-implicit shock-capturing method is proposed provided that the Jacobian of the soruce terms possesses certain properties. The proposed semi-implicit method can be viewed as a variant of the Bussing and Murman point-implicit scheme with a more appropriate numerical dissipation for the computation of strong shock waves. However, if the stiffness is not solely dominated by the source terms, a fully implicit method would be a better choice. The situation is complicated by problems that are higher than one dimension, and the presence of stiff source terms further complicates the solution procedures for alternating direction implicit (ADI) methods. Several alternatives are discussed. The primary motivation for constructing these schemes was to address thermally and chemically nonequilibrium flows in the hypersonic regime. Due to the unique structure of the eigenvalues and eigenvectors for fluid flows of this type, the computation can be simplified, thus providing a more efficient solution procedure than one might have anticipated.

  4. Semi-implicit and fully implicit shock-capturing methods for hyperbolic conservation laws with stiff source terms

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Shinn, Judy L.

    1987-01-01

    Some numerical aspects of finite-difference algorithms for nonlinear multidimensional hyperbolic conservation laws with stiff nonhomogeneous (source) terms are discussed. If the stiffness is entirely dominated by the source term, a semi-implicit shock-capturing method is proposed provided that the Jacobian of the source terms possesses certain properties. The proposed semi-implicit method can be viewed as a variant of the Bussing and Murman point-implicit scheme with a more appropriate numerical dissipation for the computation of strong shock waves. However, if the stiffness is not solely dominated by the source terms, a fully implicit method would be a better choice. The situation is complicated by problems that are higher than one dimension, and the presence of stiff source terms further complicates the solution procedures for alternating direction implicit (ADI) methods. Several alternatives are discussed. The primary motivation for constructing these schemes was to address thermally and chemically nonequilibrium flows in the hypersonic regime. Due to the unique structure of the eigenvalues and eigenvectors for fluid flows of this type, the computation can be simplified, thus providing a more efficient solution procedure than one might have anticipated.

  5. Extending the Implicit Association Test (IAT): Assessing Consumer Attitudes Based on Multi-Dimensional Implicit Associations

    PubMed Central

    Gattol, Valentin; Sääksjärvi, Maria; Carbon, Claus-Christian

    2011-01-01

    Background The authors present a procedural extension of the popular Implicit Association Test (IAT; [1]) that allows for indirect measurement of attitudes on multiple dimensions (e.g., safe–unsafe; young–old; innovative–conventional, etc.) rather than on a single evaluative dimension only (e.g., good–bad). Methodology/Principal Findings In two within-subjects studies, attitudes toward three automobile brands were measured on six attribute dimensions. Emphasis was placed on evaluating the methodological appropriateness of the new procedure, providing strong evidence for its reliability, validity, and sensitivity. Conclusions/Significance This new procedure yields detailed information on the multifaceted nature of brand associations that can add up to a more abstract overall attitude. Just as the IAT, its multi-dimensional extension/application (dubbed md-IAT) is suited for reliably measuring attitudes consumers may not be consciously aware of, able to express, or willing to share with the researcher [2], [3]. PMID:21246037

  6. Implicit Learning in Children and Adolescents with Mental Retardation.

    ERIC Educational Resources Information Center

    Vinter, Annie; Detable, Christelle

    2003-01-01

    A study compared the implicit learning of 58 children (ages 7-14) with mental retardation and 53 controls (ages 3-8). Individuals with mental retardation modified their behavior after an implicit training procedure similar to the controls. The effect of implicit learning did not vary as a function of IQ or age. (Contains references.) (Author/CR)

  7. Comparison of fully internally and strongly contracted multireference configuration interaction procedures.

    PubMed

    Sivalingam, Kantharuban; Krupicka, Martin; Auer, Alexander A; Neese, Frank

    2016-08-01

    Multireference (MR) methods occupy an important class of approaches in quantum chemistry. In many instances, for example, in studying complex magnetic properties of transition metal complexes, they are actually the only physically satisfactory choice. In traditional MR approaches, single and double excitations are performed with respect to all reference configurations (or configuration state functions, CSFs), which leads to an explosive increase of computational cost for larger reference spaces. This can be avoided by the internal contraction scheme proposed by Meyer and Siegbahn, which effectively reduces the number of wavefunction parameters to their single-reference counterpart. The "fully internally contracted" scheme (FIC) is well known from the popular CASPT2 approach. An even shorter expansion of the wavefunction is possible with the "strong contraction" (SC) scheme proposed by Angeli and Malrieu in their NEVPT2 approach. Promising multireference configuration interaction formulations (MRCI) employing internal contraction and strong contraction have been reported by several authors. In this work, we report on the implementation of the FIC-MRCI and SC-MRCI methodologies, using a computer assisted implementation strategy. The methods are benchmarked against the traditional uncontracted MRCI approach for ground and excited states of small molecules (N2, O2, CO, CO(+), OH, CH, and CN). For ground states, the comparison includes the "partially internally contracted" MRCI based on the Celani-Werner ansatz (PC-MRCI). For the three contraction schemes, the average errors range from 2% to 6% of the uncontracted MRCI correlation energies. Excitation energies are reproduced with ∼0.2 eV accuracy. In most cases, the agreement is better than 0.2 eV, even in cases with very large differential correlation contributions as exemplified for the d-d and ligand-to-metal charge transfer transitions of a Cu[NH3]4 (2+) model complex. The benchmark is supplemented with the

  8. Comparison of fully internally and strongly contracted multireference configuration interaction procedures

    NASA Astrophysics Data System (ADS)

    Sivalingam, Kantharuban; Krupicka, Martin; Auer, Alexander A.; Neese, Frank

    2016-08-01

    Multireference (MR) methods occupy an important class of approaches in quantum chemistry. In many instances, for example, in studying complex magnetic properties of transition metal complexes, they are actually the only physically satisfactory choice. In traditional MR approaches, single and double excitations are performed with respect to all reference configurations (or configuration state functions, CSFs), which leads to an explosive increase of computational cost for larger reference spaces. This can be avoided by the internal contraction scheme proposed by Meyer and Siegbahn, which effectively reduces the number of wavefunction parameters to their single-reference counterpart. The "fully internally contracted" scheme (FIC) is well known from the popular CASPT2 approach. An even shorter expansion of the wavefunction is possible with the "strong contraction" (SC) scheme proposed by Angeli and Malrieu in their NEVPT2 approach. Promising multireference configuration interaction formulations (MRCI) employing internal contraction and strong contraction have been reported by several authors. In this work, we report on the implementation of the FIC-MRCI and SC-MRCI methodologies, using a computer assisted implementation strategy. The methods are benchmarked against the traditional uncontracted MRCI approach for ground and excited states of small molecules (N2, O2, CO, CO+, OH, CH, and CN). For ground states, the comparison includes the "partially internally contracted" MRCI based on the Celani-Werner ansatz (PC-MRCI). For the three contraction schemes, the average errors range from 2% to 6% of the uncontracted MRCI correlation energies. Excitation energies are reproduced with ˜0.2 eV accuracy. In most cases, the agreement is better than 0.2 eV, even in cases with very large differential correlation contributions as exemplified for the d-d and ligand-to-metal charge transfer transitions of a Cu [NH 3 ] 4 2 + model complex. The benchmark is supplemented with the

  9. Universal single level implicit algorithm for gasdynamics

    NASA Technical Reports Server (NTRS)

    Lombard, C. K.; Venkatapthy, E.

    1984-01-01

    A single level effectively explicit implicit algorithm for gasdynamics is presented. The method meets all the requirements for unconditionally stable global iteration over flows with mixed supersonic and supersonic zones including blunt body flow and boundary layer flows with strong interaction and streamwise separation. For hyperbolic (supersonic flow) regions the method is automatically equivalent to contemporary space marching methods. For elliptic (subsonic flow) regions, rapid convergence is facilitated by alternating direction solution sweeps which bring both sets of eigenvectors and the influence of both boundaries of a coordinate line equally into play. Point by point updating of the data with local iteration on the solution procedure at each spatial step as the sweeps progress not only renders the method single level in storage but, also, improves nonlinear accuracy to accelerate convergence by an order of magnitude over related two level linearized implicit methods. The method derives robust stability from the combination of an eigenvector split upwind difference method (CSCM) with diagonally dominant ADI(DDADI) approximate factorization and computed characteristic boundary approximations.

  10. A weighted reverse Cuthill-McKee procedure for finite element method algorithms to solve strongly anisotropic electrodynamic problems

    SciTech Connect

    Cristofolini, Andrea; Latini, Chiara; Borghi, Carlo A.

    2011-02-01

    This paper presents a technique for improving the convergence rate of a generalized minimum residual (GMRES) algorithm applied for the solution of a algebraic system produced by the discretization of an electrodynamic problem with a tensorial electrical conductivity. The electrodynamic solver considered in this work is a part of a magnetohydrodynamic (MHD) code in the low magnetic Reynolds number approximation. The code has been developed for the analysis of MHD interaction during the re-entry phase of a space vehicle. This application is a promising technique intensively investigated for the shock mitigation and the vehicle control in the higher layers of a planetary atmosphere. The medium in the considered application is a low density plasma, characterized by a tensorial conductivity. This is a result of the behavior of the free electric charges, which tend to drift in a direction perpendicular both to the electric field and to the magnetic field. In the given approximation, the electrodynamics is described by an elliptical partial differential equation, which is solved by means of a finite element approach. The linear system obtained by discretizing the problem is solved by means of a GMRES iterative method with an incomplete LU factorization threshold preconditioning. The convergence of the solver appears to be strongly affected by the tensorial characteristic of the conductivity. In order to deal with this feature, the bandwidth reduction in the coefficient matrix is considered and a novel technique is proposed and discussed. First, the standard reverse Cuthill-McKee (RCM) procedure has been applied to the problem. Then a modification of the RCM procedure (the weighted RCM procedure, WRCM) has been developed. In the last approach, the reordering is performed taking into account the relation between the mesh geometry and the magnetic field direction. In order to investigate the effectiveness of the methods, two cases are considered. The RCM and WRCM procedures

  11. Global Asymptotic Behavior of Iterative Implicit Schemes

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Sweby, P. K.

    1994-01-01

    The global asymptotic nonlinear behavior of some standard iterative procedures in solving nonlinear systems of algebraic equations arising from four implicit linear multistep methods (LMMs) in discretizing three models of 2 x 2 systems of first-order autonomous nonlinear ordinary differential equations (ODEs) is analyzed using the theory of dynamical systems. The iterative procedures include simple iteration and full and modified Newton iterations. The results are compared with standard Runge-Kutta explicit methods, a noniterative implicit procedure, and the Newton method of solving the steady part of the ODEs. Studies showed that aside from exhibiting spurious asymptotes, all of the four implicit LMMs can change the type and stability of the steady states of the differential equations (DEs). They also exhibit a drastic distortion but less shrinkage of the basin of attraction of the true solution than standard nonLMM explicit methods. The simple iteration procedure exhibits behavior which is similar to standard nonLMM explicit methods except that spurious steady-state numerical solutions cannot occur. The numerical basins of attraction of the noniterative implicit procedure mimic more closely the basins of attraction of the DEs and are more efficient than the three iterative implicit procedures for the four implicit LMMs. Contrary to popular belief, the initial data using the Newton method of solving the steady part of the DEs may not have to be close to the exact steady state for convergence. These results can be used as an explanation for possible causes and cures of slow convergence and nonconvergence of steady-state numerical solutions when using an implicit LMM time-dependent approach in computational fluid dynamics.

  12. Implicit and semi-implicit schemes: Algorithms

    NASA Astrophysics Data System (ADS)

    Keppens, R.; Tóth, G.; Botchev, M. A.; van der Ploeg, A.

    1999-06-01

    This study formulates general guidelines to extend an explicit code with a great variety of implicit and semi-implicit time integration schemes. The discussion is based on their specific implementation in the Versatile Advection Code, which is a general purpose software package for solving systems of non-linear hyperbolic (and/or parabolic) partial differential equations, using standard high resolution shock capturing schemes. For all combinations of explicit high resolution schemes with implicit and semi-implicit treatments, it is shown how second-order spatial and temporal accuracy for the smooth part of the solutions can be maintained. Strategies to obtain steady state and time accurate solutions implicitly are discussed. The implicit and semi-implicit schemes require the solution of large linear systems containing the Jacobian matrix. The Jacobian matrix itself is calculated numerically to ensure the generality of this implementation. Three options are discussed in terms of applicability, storage requirements and computational efficiency. One option is the easily implemented matrix-free approach, but the Jacobian matrix can also be calculated by using a general grid masking algorithm, or by an efficient implementation for a specific Lax-Friedrich-type total variation diminishing (TVD) spatial discretization. The choice of the linear solver depends on the dimensionality of the problem. In one dimension, a direct block tridiagonal solver can be applied, while in more than one spatial dimension, a conjugate gradient (CG)-type iterative solver is used. For advection-dominated problems, preconditioning is needed to accelerate the convergence of the iterative schemes. The modified block incomplete LU-preconditioner is implemented, which performs very well. Examples from two-dimensional hydrodynamic and magnetohydrodynamic computations are given. They model transonic stellar outflow and recover the complex magnetohydrodynamic bow shock flow in the switch-on regime

  13. Implicit plasma simulation

    SciTech Connect

    Langdon, A.B.

    1985-03-03

    Implicit time integration methods have been used extensively in numerical modelling of slowly varying phenomena in systems that also support rapid variation. Examples include diffusion, hydrodynamics and reaction kinetics. This article discussed implementation of implicit time integration in plasma codes of the ''particle-in-cell'' family, and the benefits to be gained.

  14. Implicit Kalman filtering

    NASA Technical Reports Server (NTRS)

    Skliar, M.; Ramirez, W. F.

    1997-01-01

    For an implicitly defined discrete system, a new algorithm for Kalman filtering is developed and an efficient numerical implementation scheme is proposed. Unlike the traditional explicit approach, the implicit filter can be readily applied to ill-conditioned systems and allows for generalization to descriptor systems. The implementation of the implicit filter depends on the solution of the congruence matrix equation (A1)(Px)(AT1) = Py. We develop a general iterative method for the solution of this equation, and prove necessary and sufficient conditions for convergence. It is shown that when the system matrices of an implicit system are sparse, the implicit Kalman filter requires significantly less computer time and storage to implement as compared to the traditional explicit Kalman filter. Simulation results are presented to illustrate and substantiate the theoretical developments.

  15. Awareness of Implicit Attitudes

    PubMed Central

    Hahn, Adam; Judd, Charles M.; Hirsh, Holen K.; Blair, Irene V.

    2013-01-01

    Research on implicit attitudes has raised questions about how well people know their own attitudes. Most research on this question has focused on the correspondence between measures of implicit attitudes and measures of explicit attitudes, with low correspondence interpreted as showing that people have little awareness of their implicit attitudes. We took a different approach and directly asked participants to predict their results on upcoming IAT measures of implicit attitudes toward five different social groups. We found that participants were surprisingly accurate in their predictions. Across four studies, predictions were accurate regardless of whether implicit attitudes were described as true attitudes or culturally learned associations (Studies 1 and 2), regardless of whether predictions were made as specific response patterns (Study 1) or as conceptual responses (Studies 2–4), and regardless of how much experience or explanation participants received before making their predictions (Study 4). Study 3 further suggested that participants’ predictions reflected unique insight into their own implicit responses, beyond intuitions about how people in general might respond. Prediction accuracy occurred despite generally low correspondence between implicit and explicit measures of attitudes, as found in prior research. All together, the research findings cast doubt on the belief that attitudes or evaluations measured by the IAT necessarily reflect unconscious attitudes. PMID:24294868

  16. Electromagnetic direct implicit PIC simulation

    SciTech Connect

    Langdon, A.B.

    1983-03-29

    Interesting modelling of intense electron flow has been done with implicit particle-in-cell simulation codes. In this report, the direct implicit PIC simulation approach is applied to simulations that include full electromagnetic fields. The resulting algorithm offers advantages relative to moment implicit electromagnetic algorithms and may help in our quest for robust and simpler implicit codes.

  17. Implicit Training of Nonnative Speech Stimuli

    ERIC Educational Resources Information Center

    Vlahou, Eleni L.; Protopapas, Athanassios; Seitz, Aaron R.

    2012-01-01

    Learning nonnative speech contrasts in adulthood has proven difficult. Standard training methods have achieved moderate effects using explicit instructions and performance feedback. In this study, the authors question preexisting assumptions by demonstrating a superiority of implicit training procedures. They trained 3 groups of Greek adults on a…

  18. The Effects of Mindfulness versus Thought Suppression on Implicit and Explicit Measures of Experiential Avoidance

    ERIC Educational Resources Information Center

    Hooper, Nic; Villatte, Matthieu; Neofotistou, Evi; McHugh, Louise

    2010-01-01

    The current study aimed to provide an implicit measure of experiential avoidance (EA). Fifty undergraduate participants were exposed to an implicit (Implicit Relational Assessment Procedure: IRAP) and an explicit (Acceptance and Action Questionnaire II: AAQ II) measure of EA. Subsequently participant's response latencies on viewing a negatively…

  19. Implicit Attitudes in Prosopagnosia

    PubMed Central

    Knutson, Kristine M.; DeTucci, Karen A.; Grafman, Jordan

    2011-01-01

    We studied a male with acquired prosopagnosia using a battery of implicit association tests (IATs) to investigate whether observing faces varying by social category would activate the patient’s implicit social biases. We also asked him to categorize faces explicitly by race, gender, and political party. The patient, G.B., was marginally slower to categorize black compared to white faces. He showed congruency effects in the race and celebrity IATs, but not in the gender or political IATs. These results indicate that G.B. possesses an implicit social sensitivity to certain facial stimuli despite an inability to overtly recognize familiar faces. The results demonstrate that social biases can be retrieved based on facial stimuli via pathways bypassing the fusiform gyri. Thus the IAT effect can be added to the list of covert recognition effects found in prosopagnosia. PMID:21414330

  20. Implicit Spacecraft Gyro Calibration

    NASA Technical Reports Server (NTRS)

    Harman, Richard; Bar-Itzhack, Itzhack Y.

    2003-01-01

    This paper presents an implicit algorithm for spacecraft onboard instrument calibration, particularly to onboard gyro calibration. This work is an extension of previous work that was done where an explicit gyro calibration algorithm was applied to the AQUA spacecraft gyros. The algorithm presented in this paper was tested using simulated data and real data that were downloaded from the Microwave Anisotropy Probe (MAP) spacecraft. The calibration tests gave very good results. A comparison between the use of the implicit calibration algorithm used here with the explicit algorithm used for AQUA spacecraft indicates that both provide an excellent estimation of the gyro calibration parameters with similar accuracies.

  1. Emotion and Implicit Timing

    PubMed Central

    Droit-Volet, Sylvie

    2016-01-01

    This study examined the effects of emotion on implicit timing. In the implicit timing task used, the participants did not receive any temporal instructions. Instead they were simply asked and trained to press a key as quickly as possible after a stimulus (response stimulus) that was separated from a preceding stimulus by a given temporal interval (reference interval duration). However, in the testing phase, the interval duration was the reference interval duration or a shorter or longer interval duration. In addition, the participants attended two sessions: a first baseline session in which no stimulus was presented during the inter-stimulus intervals, and a second emotional session in which emotional facial expressions (angry, neutral and sad facial expressions) were presented during these intervals. Results showed faster RTs for interval durations close to the reference duration in both the baseline and the emotional conditions and yielded a U-shaped curve. This suggests that implicit processing of time persists in emotional contexts. In addition, the RT was faster for the facial expressions of anger than for those of neutrality and sadness. However, the U-shaped RT curve did not peak clearly at a shorter interval duration for the angry than for the other facial expressions. This lack of time distortion in an implicit timing task in response to arousing emotional stimuli questions the idea of an automatic speeding-up of the interval clock system involved in the representation of time. PMID:27380409

  2. Sexual Murderers' Implicit Theories

    ERIC Educational Resources Information Center

    Beech, Anthony; Fisher, Dawn; Ward, Tony

    2005-01-01

    Interviews with 28 sexual murderers were subjected to grounded theory analysis. Five implicit theories (ITs) were identified: dangerous world, male sex drive is uncontrollable, entitlement, women as sexual objects, and women as unknowable. These ITs were found to be identical to those identified in the literature as being present in rapists. The…

  3. Implicit Learning as an Ability

    ERIC Educational Resources Information Center

    Kaufman, Scott Barry; DeYoung, Caroline G.; Gray, Jeremy R.; Jimenez, Luis; Brown, Jamie; Mackintosh, Nicholas

    2010-01-01

    The ability to automatically and implicitly detect complex and noisy regularities in the environment is a fundamental aspect of human cognition. Despite considerable interest in implicit processes, few researchers have conceptualized implicit learning as an ability with meaningful individual differences. Instead, various researchers (e.g., Reber,…

  4. Measuring individual and cultural differences in implicit trait theories.

    PubMed

    Church, A Timothy; Ortiz, Fernando A; Katigbak, Marcia S; Avdeyeva, Tatyana V; Emerson, Alice M; Vargas Flores, José de Jesús; Ibáñez Reyes, Joselina

    2003-08-01

    A new measure of implicit theories or beliefs regarding the traitedness versus contextuality of behavior was developed and tested across cultures. In Studies 1 (N = 266) and 2 (N = 266), these implicit beliefs dimensions were reliably measured and replicated across U.S. college student samples and validity evidence was provided. In Study 3, their structure replicated well across an individualistic culture (the United States; N = 249) and a collectivistic culture (Mexico; N = 268). Implicit trait and contextual beliefs overlapped only modestly with implicit entity theory beliefs and were predicted by self-construals in ways that generally supported cultural psychology hypotheses. Implicit trait beliefs were fairly strongly endorsed in both cultures, suggesting that such beliefs may be universally held. PMID:12916574

  5. The Effects of Implicit Instruction on Implicit and Explicit Knowledge Development

    ERIC Educational Resources Information Center

    Godfroid, Aline

    2016-01-01

    This study extends the evidence for implicit second language (L2) learning, which comes largely from (semi-)artificial language research, to German. Upper-intermediate L2 German learners were flooded with spoken exemplars of a difficult morphological structure, namely strong, vowel-changing verbs. Toward the end of exposure, the mandatory vowel…

  6. Effects of brief mindful acceptance induction on implicit dysfunctional attitudes and concordance between implicit and explicit dysfunctional attitudes.

    PubMed

    Keng, Shian-Ling; Seah, Stanley T H; Tong, Eddie M W; Smoski, Moria

    2016-08-01

    Mindfulness-based interventions have been shown to be effective in alleviating depressive symptoms. While much work has examined the effects of mindfulness training on subjective symptoms and experiences, and less is known regarding whether mindfulness training may alter relatively uncontrollable cognitive processes associated with depressed mood, particularly implicit dysfunctional attitudes. The present study examined the effects of a brief mindful acceptance induction on implicit dysfunctional attitudes and degree of concordance between implicit and explicit dysfunctional attitudes in the context of sad mood. A total of 79 adult participants with elevated depressive symptoms underwent an autobiographical mood induction procedure before being randomly assigned to mindful acceptance or thought wandering inductions. Results showed that the effect of mindful acceptance on implicit dysfunctional attitude was significantly moderated by trait mindfulness. Participants high on trait mindfulness demonstrated significant improvements in implicit dysfunctional attitudes following the mindful acceptance induction. Those low on trait mindfulness demonstrated significantly worse implicit dysfunctional attitudes following the induction. Significantly greater levels of concordance between implicit and explicit dysfunctional attitudes were observed in the mindful acceptance condition versus the thought wandering condition. The findings highlight changes in implicit dysfunctional attitudes and improvements in self-concordance as two potential mechanisms underlying the effects of mindfulness-based interventions. PMID:27236073

  7. Do children with developmental dyslexia have an implicit learning deficit?

    PubMed Central

    Vicari, S; Finzi, A; Menghini, D; Marotta, L; Baldi, S; Petrosini, L

    2005-01-01

    Objective: The purpose of this study was to investigate the effects of specific types of tasks on the efficiency of implicit procedural learning in the presence of developmental dyslexia (DD). Methods: Sixteen children with DD (mean (SD) age 11.6 (1.4) years) and 16 matched normal reader controls (mean age 11.4 (1.9) years) were administered two tests (the Serial Reaction Time test and the Mirror Drawing test) in which implicit knowledge was gradually acquired across multiple trials. Although both tests analyse implicit learning abilities, they tap different competencies. The Serial Reaction Time test requires the development of sequential learning and little (if any) procedural learning, whereas the Mirror Drawing test involves fast and repetitive processing of visuospatial stimuli but no acquisition of sequences. Results: The children with DD were impaired on both implicit learning tasks, suggesting that the learning deficit observed in dyslexia does not depend on the material to be learned (with or without motor sequence of response action) but on the implicit nature of the learning that characterises the tasks. Conclusion: Individuals with DD have impaired implicit procedural learning. PMID:16170083

  8. Implicit measure for yoga research: Yoga implicit association test

    PubMed Central

    Ilavarasu, Judu V; Rajesh, Sasidharan K; Hankey, Alex

    2014-01-01

    Context: The implicit association test (IAT), a new tool for yoga research is presented. Implicit measures could be used in those situations where (1) The construct is difficult to self-report, (2) there is a threat of social desirability. Clinically, we can assess cognitive dissonance by evaluating incongruence between implicit and explicit measures. Explicit preferences are self-reported. Implicit preferences are what we inherently believe, often without our conscious awareness. Aims: The primary objective of this study is to provide a bird's eye view of the field, implicit cognition, with emphasis on the IAT and the secondary objective is to illustrate through an example of our study to develop an implicit tool to assess implicit preference toward yoga. Settings and Design: A total of 5 independent samples of total 69 students undergoing short and long-term yoga courses in a Yoga University were assessed for their implicit and explicit preferences towards yoga. Materials and Methods: The yoga-IAT (Y-IAT), explicit self-rating scale was administered through computers using the Inquisit program by Millisecond Software. Experimental and scoring materials are provided. Results: A moderate preference toward yoga was detected, with a lower implicit-explicit congruence, reflecting possible confound of social desirability in the self-report of preference toward yoga. Conclusions: Implicit measures may be used in the yoga field to assess constructs, which are difficult to self-report or may have social desirability threat. Y-IAT may be used to evaluate implicit preference toward yoga. PMID:25035621

  9. Implicit Shape Parameterization for Kansei Design Methodology

    NASA Astrophysics Data System (ADS)

    Nordgren, Andreas Kjell; Aoyama, Hideki

    Implicit shape parameterization for Kansei design is a procedure that use 3D-models, or concepts, to span a shape space for surfaces in the automotive field. A low-dimensional, yet accurate shape descriptor was found by Principal Component Analysis of an ensemble of point-clouds, which were extracted from mesh-based surfaces modeled in a CAD-program. A theoretical background of the procedure is given along with step-by-step instructions for the required data-processing. The results show that complex surfaces can be described very efficiently, and encode design features by an implicit approach that does not rely on error-prone explicit parameterizations. This provides a very intuitive way to explore shapes for a designer, because various design features can simply be introduced by adding new concepts to the ensemble. Complex shapes have been difficult to analyze with Kansei methods due to the large number of parameters involved, but implicit parameterization of design features provides a low-dimensional shape descriptor for efficient data collection, model-building and analysis of emotional content in 3D-surfaces.

  10. Implicit beliefs about ideal body image predict body image dissatisfaction

    PubMed Central

    Heider, Niclas; Spruyt, Adriaan; De Houwer, Jan

    2015-01-01

    We examined whether implicit measures of actual and ideal body image can be used to predict body dissatisfaction in young female adults. Participants completed two Implicit Relational Assessment Procedures (IRAPs) to examine their implicit beliefs concerning actual (e.g., I am thin) and desired ideal body image (e.g., I want to be thin). Body dissatisfaction was examined via self-report questionnaires and rating scales. As expected, differences in body dissatisfaction exerted a differential influence on the two IRAP scores. Specifically, the implicit belief that one is thin was lower in participants who exhibited a high degree of body dissatisfaction than in participants who exhibited a low degree of body dissatisfaction. In contrast, the implicit desire to be thin (i.e., thin ideal body image) was stronger in participants who exhibited a high level of body dissatisfaction than in participants who were less dissatisfied with their body. Adding further weight to the idea that both IRAP measures captured different underlying constructs, we also observed that they correlated differently with body mass index, explicit body dissatisfaction, and explicit measures of actual and ideal body image. More generally, these findings underscore the advantage of using implicit measures that incorporate relational information relative to implicit measures that allow for an assessment of associative relations only. PMID:26500567

  11. Implicit Lagrange-Routh equations and Dirac reduction

    NASA Astrophysics Data System (ADS)

    García-Toraño Andrés, Eduardo; Mestdag, Tom; Yoshimura, Hiroaki

    2016-06-01

    In this paper, we make a generalization of Routh's reduction method for Lagrangian systems with symmetry to the case where not any regularity condition is imposed on the Lagrangian. First, we show how implicit Lagrange-Routh equations can be obtained from the Hamilton-Pontryagin principle, by making use of an anholonomic frame, and how these equations can be reduced. To do this, we keep the momentum constraint implicit throughout and we make use of a Routhian function defined on a certain submanifold of the Pontryagin bundle. Then, we show how the reduced implicit Lagrange-Routh equations can be described in the context of dynamical systems associated to Dirac structures, in which we fully utilize a symmetry reduction procedure for implicit Hamiltonian systems with symmetry.

  12. Implicit Sequence Learning in Children.

    ERIC Educational Resources Information Center

    Meulemans, Thierry; Van der Linden, Martial; Perruchet, Pierre

    1998-01-01

    Examined implicit learning ability in 6- and 10-year olds and adults as assessed by a serial reaction-time task, along with retention of knowledge after one week and explicit knowledge developed by children. Found no age-related difference in serial reaction-time performance, consistent with the idea that implicit learning abilities may be…

  13. Implicit Theories of Peer Relationships

    ERIC Educational Resources Information Center

    Rudolph, Karen D.

    2010-01-01

    This research investigated the role of children's implicit theories of peer relationships in their psychological, emotional, and behavioral adjustment. Participants included 206 children (110 girls; 96 boys; M age = 10.13 years, SD = 1.16) who reported on their implicit theories of peer relationships, social goal orientation, need for approval,…

  14. Implicit emotion perception in schizophrenia.

    PubMed

    Trémeau, Fabien; Antonius, Daniel; Todorov, Alexander; Rebani, Yasmina; Ferrari, Kelsey; Lee, Sang Han; Calderone, Daniel; Nolan, Karen A; Butler, Pamela; Malaspina, Dolores; Javitt, Daniel C

    2015-12-01

    Explicit but not implicit facial emotion perception has been shown to be impaired in schizophrenia. In this study, we used newly developed technology in social neuroscience to examine implicit emotion processing. It has been shown that when people look at faces, they automatically infer social traits, and these trait judgments rely heavily on facial features and subtle emotion expressions even with neutral faces. Eighty-one individuals with schizophrenia or schizoaffective disorder and 62 control subjects completed a computer task with 30 well-characterized neutral faces. They rated each face on 10 trait judgments: attractive, mean, trustworthy, intelligent, dominant, fun, sociable, aggressive, emotionally stable and weird. The degree to which trait ratings were predicted by objectively-measured subtle emotion expressions served as a measure of implicit emotion processing. Explicit emotion recognition was also examined. Trait ratings were significantly predicted by subtle facial emotional expressions in controls and patients. However, impairment in the implicit emotion perception of fear, happiness, anger and surprise was found in patients. Moreover, these deficits were associated with poorer everyday problem-solving skills and were relatively independent of explicit emotion recognition. Implicit emotion processing is impaired in patients with schizophrenia or schizoaffective disorder. Deficits in implicit and explicit emotion perception independently contribute to the patients' poor daily life skills. More research is needed to fully understand the role of implicit and explicit processes in the functional deficits of patients, in order to develop targeted and useful remediation interventions. PMID:26473695

  15. A diagonally inverted LU implicit multigrid scheme

    NASA Technical Reports Server (NTRS)

    Yokota, Jeffrey W.; Caughey, David A.; Chima, Rodrick V.

    1988-01-01

    A new Diagonally Inverted LU Implicit scheme is developed within the framework of the multigrid method for the 3-D unsteady Euler equations. The matrix systems that are to be inverted in the LU scheme are treated by local diagonalizing transformations that decouple them into systems of scalar equations. Unlike the Diagonalized ADI method, the time accuracy of the LU scheme is not reduced since the diagonalization procedure does not destroy time conservation. Even more importantly, this diagonalization significantly reduces the computational effort required to solve the LU approximation and therefore transforms it into a more efficient method of numerically solving the 3-D Euler equations.

  16. Agglomeration multigrid methods with implicit Runge-Kutta smoothers applied to aerodynamic simulations on unstructured grids

    NASA Astrophysics Data System (ADS)

    Langer, Stefan

    2014-11-01

    For unstructured finite volume methods an agglomeration multigrid with an implicit multistage Runge-Kutta method as a smoother is developed for solving the compressible Reynolds averaged Navier-Stokes (RANS) equations. The implicit Runge-Kutta method is interpreted as a preconditioned explicit Runge-Kutta method. The construction of the preconditioner is based on an approximate derivative. The linear systems are solved approximately with a symmetric Gauss-Seidel method. To significantly improve this solution method grid anisotropy is treated within the Gauss-Seidel iteration in such a way that the strong couplings in the linear system are resolved by tridiagonal systems constructed along these directions of strong coupling. The agglomeration strategy is adapted to this procedure by taking into account exactly these anisotropies in such a way that a directional coarsening is applied along these directions of strong coupling. Turbulence effects are included by a Spalart-Allmaras model, and the additional transport-type equation is approximately solved in a loosely coupled manner with the same method. For two-dimensional and three-dimensional numerical examples and a variety of differently generated meshes we show the wide range of applicability of the solution method. Finally, we exploit the GMRES method to determine approximate spectral information of the linearized RANS equations. This approximate spectral information is used to discuss and compare characteristics of multistage Runge-Kutta methods.

  17. Gender Differences in Implicit Moral Orientation Associations: The Justice and Care Debate Revisited

    ERIC Educational Resources Information Center

    Agerstrom, Jens; Bjorklund, Fredrik; Carlsson, Rickard

    2011-01-01

    Employing new measures (Implicit Association Test) to study the classic issue of moral orientations, we predicted and found gender differences in implicit associations to the concepts of justice and care. Specifically, we found that men more strongly associate justice vs. care with importance and with themselves than women. However, participants'…

  18. [Effects of color on implicit and explicit memory tests].

    PubMed

    Wippich, W; Mecklenbräuker, S; Baumann, R

    1994-01-01

    We report two experiments that explore why recent investigations of implicit memory did not find any effects of color information on test performance. The argument that previous failures to find effects of repetition priming were due to an arbitrary association between objects and colors was found to be wanting. To the contrary, both experiments showed no or small effects of repetition for objects paired with their prototypical colors. A second argument according to which subjects attend to the colors at encoding did not fare much better. More importantly, however, we found strong effects of repetition priming with a conceptual implicit memory measure, whereas previous research had relied exclusively on perceptual tests of implicit memory. In both experiments, the subjects were asked to choose a suitable color for each object at testing. No instructions about remembering the objects were given. The results demonstrated strong preferences for the previously seen colors in the color-choice task. Furthermore, this effect was present to the same extent with picture objects and with object names, corroborating the conceptual nature of the implicit memory measure. Finally, we observed many functional dissociations with explicit measures of memory for color information, demonstrating implicit use of memory in the conceptual choice-test for colors. PMID:7941623

  19. [Using the Implicit Association Test (IAT) to measure implicit shyness].

    PubMed

    Aikawa, Atsushi; Fujii, Tsutomu

    2011-04-01

    Previous research has shown that implicitly measured shyness predicted spontaneous shy behavior in social situations, while explicit self-ratings of shyness predicted controlled shy behavior (Asendorpf, Banse, & Mücke, 2002). The present study examined whether these same results would be replicated in Japan. In Study 1, college students (N=47) completed a shyness Implicit Association Test (IAT for shyness) and explicit self-ratings of shyness. In Study 2, friends (N=69) of the Study 1 participants rated those participants on various personality scales. Covariance structure analysis, revealed that only implicit self-concept measured by the shyness IAT predicted other-rated high interpersonal tension (spontaneous shy behavior). Also, only explicit self-concept predicted other-rated low praise seeking (controlled shy behavior). The results of this study are similar to the findings of the previous research. PMID:21706822

  20. A comparison of implicit numerical methods for solving the transient spherical diffusion equation

    NASA Technical Reports Server (NTRS)

    Curry, D. M.

    1977-01-01

    Comparative numerical temperature results obtained by using two implicit finite difference procedures for the solution of the transient diffusion equation in spherical coordinates are presented. The validity and accuracy of these solutions are demonstrated by comparison with exact analytical solutions.

  1. Measures of Implicit and Explicit Attitudes toward Mainstream and BDSM Sexual Terms Using the IRAP and Questionnaire with BDSM/Fetish and Student Participants

    ERIC Educational Resources Information Center

    Stockwell, Fawna M. J.; Walker, Diana J.; Eshleman, John W.

    2010-01-01

    The Implicit Relational Assessment Procedure (IRAP) examines implicit attitudes through the measurement of response latencies. In this study, the IRAP was used to assess implicit attitudes toward "mainstream" sexual terms (e.g., Kissing) and "BDSM" terms (e.g., Bondage) among individuals reporting BDSM interests and among students who did not…

  2. Posture modulates implicit hand maps.

    PubMed

    Longo, Matthew R

    2015-11-01

    Several forms of somatosensation require that afferent signals be informed by stored representations of body size and shape. Recent results have revealed that position sense relies on a highly distorted body representation. Changes of internal hand posture produce plastic alterations of processing in somatosensory cortex. This study therefore investigated how such postural changes affect implicit body representations underlying position sense. Participants localised the knuckles and tips of each finger in external space in two postures: the fingers splayed (Apart posture) or pressed together (Together posture). Comparison of the relative locations of the judgments of each landmark were used to construct implicit maps of represented hand structure. Spreading the fingers apart produced increases in the implicit representation of hand size, with no apparent effect on hand shape. Thus, changes of internal hand posture produce rapid modulation of how the hand itself is represented, paralleling the known effects on somatosensory cortical processing. PMID:26117153

  3. Changing theories of change: strategic shifting in implicit theory endorsement.

    PubMed

    Leith, Scott A; Ward, Cindy L P; Giacomin, Miranda; Landau, Enoch S; Ehrlinger, Joyce; Wilson, Anne E

    2014-10-01

    People differ in their implicit theories about the malleability of characteristics such as intelligence and personality. These relatively chronic theories can be experimentally altered, and can be affected by parent or teacher feedback. Little is known about whether people might selectively shift their implicit beliefs in response to salient situational goals. We predicted that, when motivated to reach a desired conclusion, people might subtly shift their implicit theories of change and stability to garner supporting evidence for their desired position. Any motivated context in which a particular lay theory would help people to reach a preferred directional conclusion could elicit shifts in theory endorsement. We examine a variety of motivated situational contexts across 7 studies, finding that people's theories of change shifted in line with goals to protect self and liked others and to cast aspersions on disliked others. Studies 1-3 demonstrate how people regulate their implicit theories to manage self-view by more strongly endorsing an incremental theory after threatening performance feedback or memories of failure. Studies 4-6 revealed that people regulate the implicit theories they hold about favored and reviled political candidates, endorsing an incremental theory to forgive preferred candidates for past gaffes but leaning toward an entity theory to ensure past failings "stick" to opponents. Finally, in Study 7, people who were most threatened by a previously convicted child sex offender (i.e., parents reading about the offender moving to their neighborhood) gravitated most to the entity view that others do not change. Although chronic implicit theories are undoubtedly meaningful, this research reveals a previously unexplored source of fluidity by highlighting the active role people play in managing their implicit theories in response to goals. PMID:25222649

  4. A novel, implicit treatment for language comprehension processes in right hemisphere brain damage: Phase I data

    PubMed Central

    Tompkins, Connie A.; Blake, Margaret T.; Wambaugh, Julie; Meigh, Kimberly

    2012-01-01

    Background This manuscript reports the initial phase of testing for a novel, “Contextual constraint” treatment, designed to stimulate inefficient language comprehension processes in adults with right hemisphere brain damage (RHD). Two versions of treatment were developed to target two normal comprehension processes that have broad relevance for discourse comprehension and that are often disrupted by RHD: coarse semantic coding and suppression. The development of the treatment was informed by two well-documented strengths of the RHD population. The first is consistently better performance on assessments that are implicit, or nearly so, than on explicit, metalinguistic measures of language and cognitive processing. The second is improved performance when given linguistic context that moderately-to-strongly biases an intended meaning. Treatment consisted of providing brief context sentences to prestimulate, or constrain, intended interpretations. Participants made no explicit associations or judgments about the constraint sentences; rather, these contexts served only as implicit primes. Aims This Phase I treatment study aimed to determine the effects of a novel, implicit, Contextual Constraint treatment in adults with RHD whose coarse coding or suppression processes were inefficient. Treatment was hypothesized to speed coarse coding or suppression function in these individuals. Methods & Procedures Three adults with RHD participated in this study, one (P1) with a coarse coding deficit and two (P2, P3) with suppression deficits. Probe tasks were adapted from prior studies of coarse coding and suppression in RHD. The dependent measure was the percentage of responses that met predetermined response time criteria. When pre-treatment baseline performance was stable, treatment was initiated. There were two levels of contextual constraint, Strong and Moderate, and treatment for each item began with the provision of the Strong constraint context. Outcomes & Results

  5. On the computational efficiency of particle dynamics simulations in the radiation belt: comparison between implicit and semi-implicit schemes

    NASA Astrophysics Data System (ADS)

    Camporeale, E.; Delzanno, G.; Zaharia, S. G.; Koller, J.

    2012-12-01

    The particle dynamics in the Earth's radiation belt is generally modeled by means of a two-dimensional diffusion equation for the particle distribution function in energy and pitch angle. In this work we survey and compare different numerical schemes for the solution of the diffusion equation, with the goal of outlining which is the optimal strategy from a numerical point of view. We focus on the general (and more computationally challenging) case where the mixed terms in the diffusion tensor are retained. We compare fully-implicit and semi-implicit schemes. For the former we have analyzed a direct solver based on a LU decomposition routine for sparse matrices, and an iterative ILU-preconditioned GMRES. For the semi-implicit scheme we have studied an Alternating Direction Implicit scheme. We present a convergence study for a realistic case that shows that the timestep and grid size are strongly constrained by the desired accuracy of the solution. We show that the fully-implicit scheme is to be preferred in most cases as the more computationally efficient.

  6. On the numerical simulation of particle dynamics in the radiation belt: 1. Implicit and semi-implicit schemes

    NASA Astrophysics Data System (ADS)

    Camporeale, E.; Delzanno, G. L.; Zaharia, S.; Koller, J.

    2013-06-01

    The particle dynamics in the Earth's radiation belt is generally modeled by means of a two-dimensional diffusion equation for the particle distribution function in energy and pitch angle. The goal of this paper is to survey and compare different numerical schemes for the solution of the diffusion equation, and to outline the optimal strategy from a numerical point of view. We focus on the general (and more computationally challenging) case where the mixed terms in the diffusion tensor are retained. In Part 1, we compare fully implicit and semi-implicit schemes. For the former, we have analyzed a direct solver based on a LU decomposition routine for sparse matrices, and an iterative incomplete LU preconditioned Generalized Minimal REsidual solver. For the semi-implicit scheme, we have studied an alternating direction implicit scheme. We present a convergence study for a realistic case that shows that the time step and grid size are strongly constrained by the desired accuracy of the solution. We show that the fully implicit scheme is to be preferred in most cases as the more computationally efficient.

  7. Semantic Generalization in Implicit Language Learning

    ERIC Educational Resources Information Center

    Paciorek, Albertyna; Williams, John N.

    2015-01-01

    Despite many years of investigation into implicit learning in nonlinguistic domains, the potential for implicit learning to deliver the kinds of generalizations that underlie natural language competence remains unclear. In a series of experiments, we investigated implicit learning of the semantic preferences of novel verbs, specifically, whether…

  8. Measuring individual differences in implicit cognition: the implicit association test.

    PubMed

    Greenwald, A G; McGhee, D E; Schwartz, J L

    1998-06-01

    An implicit association test (IAT) measures differential association of 2 target concepts with an attribute. The 2 concepts appear in a 2-choice task (2-choice task (e.g., flower vs. insect names), and the attribute in a 2nd task (e.g., pleasant vs. unpleasant words for an evaluation attribute). When instructions oblige highly associated categories (e.g., flower + pleasant) to share a response key, performance is faster than when less associated categories (e.g., insect & pleasant) share a key. This performance difference implicitly measures differential association of the 2 concepts with the attribute. In 3 experiments, the IAT was sensitive to (a) near-universal evaluative differences (e.g., flower vs. insect), (b) expected individual differences in evaluative associations (Japanese + pleasant vs. Korean + pleasant for Japanese vs. Korean subjects), and (c) consciously disavowed evaluative differences (Black + pleasant vs. White + pleasant for self-described unprejudiced White subjects). PMID:9654756

  9. Revealing children's implicit spelling representations.

    PubMed

    Critten, Sarah; Pine, Karen J; Messer, David J

    2013-06-01

    Conceptualizing the underlying representations and cognitive mechanisms of children's spelling development is a key challenge for literacy researchers. Using the Representational Redescription model (Karmiloff-Smith), Critten, Pine and Steffler (2007) demonstrated that the acquisition of phonological and morphological knowledge may be underpinned by increasingly explicit levels of spelling representation. However, their proposal that implicit representations may underlie early 'visually based' spelling remains unresolved. Children (N = 101, aged 4-6 years) were given a recognition task (Critten et al., 2007) and a novel production task, both involving verbal justifications of why spellings are correct/incorrect, strategy use and word pattern similarity. Results for both tasks supported an implicit level of spelling characterized by the ability to correctly recognize/produce words but the inability to explain operational strategies or generalize knowledge. Explicit levels and multiple representations were also in evidence across the two tasks. Implications for cognitive mechanisms underlying spelling development are discussed. PMID:23659891

  10. Implicit Racial Biases in Preschool Children and Adults From Asia and Africa.

    PubMed

    Qian, Miao K; Heyman, Gail D; Quinn, Paul C; Messi, Francoise A; Fu, Genyue; Lee, Kang

    2016-01-01

    This research used an Implicit Racial Bias Test to investigate implicit racial biases among 3- to 5-year-olds and adult participants in China (N = 213) and Cameroon (N = 257). In both cultures, participants displayed high levels of racial biases that remained stable between 3 and 5 years of age. Unlike adults, young children's implicit racial biases were unaffected by the social status of the other-race groups. Also, unlike adults, young children displayed overt explicit racial biases, and these biases were dissociated from their implicit biases. The results provide strong evidence for the early emergence of implicit racial biases and point to the need to reduce them in early childhood. PMID:26435128

  11. Ego depletion impairs implicit learning.

    PubMed

    Thompson, Kelsey R; Sanchez, Daniel J; Wesley, Abigail H; Reber, Paul J

    2014-01-01

    Implicit skill learning occurs incidentally and without conscious awareness of what is learned. However, the rate and effectiveness of learning may still be affected by decreased availability of central processing resources. Dual-task experiments have generally found impairments in implicit learning, however, these studies have also shown that certain characteristics of the secondary task (e.g., timing) can complicate the interpretation of these results. To avoid this problem, the current experiments used a novel method to impose resource constraints prior to engaging in skill learning. Ego depletion theory states that humans possess a limited store of cognitive resources that, when depleted, results in deficits in self-regulation and cognitive control. In a first experiment, we used a standard ego depletion manipulation prior to performance of the Serial Interception Sequence Learning (SISL) task. Depleted participants exhibited poorer test performance than did non-depleted controls, indicating that reducing available executive resources may adversely affect implicit sequence learning, expression of sequence knowledge, or both. In a second experiment, depletion was administered either prior to or after training. Participants who reported higher levels of depletion before or after training again showed less sequence-specific knowledge on the post-training assessment. However, the results did not allow for clear separation of ego depletion effects on learning versus subsequent sequence-specific performance. These results indicate that performance on an implicitly learned sequence can be impaired by a reduction in executive resources, in spite of learning taking place outside of awareness and without conscious intent. PMID:25275517

  12. [Psychological theory and implicit sociology.].

    PubMed

    Sévigny, R

    1983-01-01

    This text is based on the hypothesis that every theory on the psychology of personality must inevitably, in one manner or another, have a sociological referent, that is to say, it must refer to a body of knowledge which deals with a diversity of social contexts and their relations to individuals. According to this working hypothesis, such a sociology is implicit. This text then discusses a group of theoretical approaches in an effort to verify this hypothesis. This approach allows the extrication of diverse forms or diverse expressions of this implicit sociology within this context several currents are rapidly explored : psychoanalysis, behaviorism, gestalt, classical theory of needs. The author also comments on the approach, inspired by oriental techniques or philosophies, which employs the notion of myth to deepen self awareness. Finally, from the same perspective, he comments at greater length on the work of Carl Rogers, highlighting the diverse form of implicit sociology. In addition to Carl Rogers, this text refers to Freud, Jung, Adler, Reich, Perls, Goodman, Skinner as well as to Ginette Paris and various analysts of Taoism. In conclusion, the author indicates the significance of his analysis from double viewpoint of psychological theory and practice. PMID:17093766

  13. An Attempt to Elaborate a Construct to Measure the Degree of Explicitness and Implicitness in ELT Materials

    ERIC Educational Resources Information Center

    Criado Sanchez, Raquel; Perez, Aquilino Sanchez; Gomez, Pascual Cantos

    2010-01-01

    The concepts of "explicit" and "implicit" (knowledge) are at the core of SLA studies. We take "explicit" as conscious and declarative (knowledge); "implicit" as unconscious, automatic and procedural (knowledge) (DeKeyser, 2003; R. Ellis, 2005a, 2005b, 2009; Hulstjin, 2005; Robinson, 1996; Schmidt, 1990, 1994). The importance of those concepts and…

  14. Implicit Attitudes towards Children with Autism versus Normally Developing Children as Predictors of Professional Burnout and Psychopathology

    ERIC Educational Resources Information Center

    Kelly, Amanda; Barnes-Holmes, Dermot

    2013-01-01

    Tutors trained in applied behaviour analysis (n = 16) and mainstream school teachers (n = 16) were exposed to an Implicit Relational Assessment Procedure (IRAP) designed to assess implicit attitudes towards individuals with autism versus normally developing individuals. Participants also completed a range of explicit measures, including measures…

  15. A non-linearly stable implicit finite element algorithm for hypersonic aerodynamics

    NASA Technical Reports Server (NTRS)

    Iannelli, G. S.; Baker, A. J.

    1992-01-01

    A generalized curvilinear coordinate Taylor weak statement implicit finite element algorithm is developed for the two-dimensional and axisymmetric compressible Navier-Stokes equations for ideal and reacting gases. For accurate hypersonic simulation, air is modeled as a mixture of five perfect gases, i.e., molecular and atomic oxygen and nitrogen as well as nitric oxide. The associated pressure is then determined via Newton solution of the classical chemical equilibrium equation system. The directional semidiscretization is achieved using an optimal metric data Galerkin finite element weak statement, on a developed 'companion conservation law system', permitting classical test and trial space definitions. Utilizing an implicit Runge-Kutta scheme, the terminal algorithm is then nonlinearly stable, and second-order accurate in space and time on arbitrary curvilinear coordinates. Subsequently, a matrix tensor product factorization procedure permits an efficient numerical linear algebra handling for large Courant numbers. For ideal- and real-gas hypersonic flows, the algorithm generates essentially nonoscillatory numerical solutions in the presence of strong detached shocks and boundary layer-inviscid flow interactions.

  16. Attitudes towards individuals with disabilities as measured by the implicit association test: a literature review.

    PubMed

    Wilson, Michelle Clare; Scior, Katrina

    2014-02-01

    Research investigating attitudes towards individuals with disabilities has largely focused on self-reported explicit attitudes. Given that factors such as social desirability may influence explicit attitudes, researchers have developed tools which instead assess less consciously controllable implicit attitudes. Considering research on implicit attitudes thus seems pertinent. A review of studies measuring implicit attitudes towards individuals with physical disabilities (visual, motor or hearing) or intellectual disabilities via the Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) was carried out. Systematic searches of PsycINFO, CINAHL, EMBASE, ERIC, MEDLINE, PUBMED, Scopus and Web of Science databases identified relevant articles published between January 2000 and September 2012. Seventeen articles (reporting on 18 studies that employed the IAT) were identified. These investigated implicit attitudes towards individuals with; physical disabilities (N=13), intellectual disabilities (N=3), both physical and intellectual disabilities (N=1), and 'unspecified disabilities' (N=1). Across all studies, moderate to strong negative implicit attitudes were found and there was little to no association between explicit and implicit attitudes. Individuals' beliefs about the controllability of their future, sensitivity to the concept of disease, and contact with individuals with disabilities appear to be associated with implicit attitudes. A consistent pattern of moderate to strong negative implicit attitudes towards individuals with disabilities was evident. These studies provide a starting point, but methodological issues related to sampling and the employed IATs limit the generalizability of these results. Further research investigating implicit attitudes towards specific disability types, with a wider subject pool are necessary as well as further investigation of factors that contribute to these attitudes. PMID:24316588

  17. Patterns of Implicit and Explicit Attitudes in Children and Adults: Tests in the Domain of Religion

    PubMed Central

    Heiphetz, Larisa; Spelke, Elizabeth S.; Banaji, Mahzarin R.

    2012-01-01

    Among the most replicated results in social cognition is the split between explicit and implicit attitudes; adults demonstrate weaker group-based preferences on explicit rather than implicit measures. However, the developmental origins of this pattern remain unclear. If implicit attitudes develop over a protracted period of time, children should not demonstrate the implicit preferences observed among adults. Additionally, unlike adults, children may report group-based preferences due to their lesser concern with social desirability. In Study 1, Christian adults showed the expected pattern of robust implicit preference but no explicit preference. In four additional experiments, 6–8 year old children whose parents identified them as Christian viewed characters described as belonging to two starkly different religious groups (“strong religious difference”) or two relatively similar religious groups (“weak religious difference”). Participants then completed explicit and implicit (IAT) measures of attitude toward Christians and either Hindus (Study 2) or Jews (Studies 3–5). Three main results emerged. First, like adults, children showed significant implicit pro-Christian preferences across all studies. Second, unlike adults, children in the “strong religious difference” case reported preferences of approximately the same magnitude as their implicit attitudes (i.e., no dissociation). Third, even in the “weak religious difference” case, children showed implicit pro-Christian preferences (although, like adults, their explicit attitudes were not sensitive to intergroup difference). These data suggest that the seeds of implicit religious preferences are sown early and that children's explicit preferences are influenced by the social distance between groups. PMID:22905875

  18. Age, race, and implicit prejudice: using process dissociation to separate the underlying components.

    PubMed

    Stewart, Brandon D; von Hippel, William; Radvansky, Gabriel A

    2009-02-01

    Older adults express greater prejudice than younger adults, but it is not clear why. In a community-based sample, we found that older White adults demonstrated more racial prejudice on an implicit measure, the race Implicit Association Test, than did younger adults. Process-dissociation procedures indicated that this difference in implicit prejudice was due to older adults having less control of their automatic prejudicial associations rather than stronger automatic prejudicial associations. Furthermore, this age difference in control was mediated by age-related deficits in inhibitory ability. White participants showed stronger automatic prejudicial associations than did Black participants. PMID:19175528

  19. Coefficient matrices for implicit finite difference solution of the inviscid fluid conservation law equations

    NASA Technical Reports Server (NTRS)

    Steger, J. L.

    1978-01-01

    Although the Navier-Stokes equations describe most flows of interest in aerodynamics, the inviscid conservation law equations may be used for small regions with viscous forces. Thus, Euler equations and several time-accurate finite difference procedures, explicit and implicit, are discussed. Although implicit techniques require more computational work, they permit larger time steps to be taken without instability. It is noted that the Jacobian matrices for Euler equations in conservation-law form have certain eigenvalue-eigenvector properties which may be used to construct conservative-form coefficient matrices. This reduces the computation time of several implicit and semiimplicit schemes. Extensions of the basic approach to other areas are suggested.

  20. Acceleration on stretched meshes with line-implicit LU-SGS in parallel implementation

    NASA Astrophysics Data System (ADS)

    Otero, Evelyn; Eliasson, Peter

    2015-02-01

    The implicit lower-upper symmetric Gauss-Seidel (LU-SGS) solver is combined with the line-implicit technique to improve convergence on the very anisotropic grids necessary for resolving the boundary layers. The computational fluid dynamics code used is Edge, a Navier-Stokes flow solver for unstructured grids based on a dual grid and edge-based formulation. Multigrid acceleration is applied with the intention to accelerate the convergence to steady state. LU-SGS works in parallel and gives better linear scaling with respect to the number of processors, than the explicit scheme. The ordering techniques investigated have shown that node numbering does influence the convergence and that the orderings from Delaunay and advancing front generation were among the best tested. 2D Reynolds-averaged Navier-Stokes computations have clearly shown the strong efficiency of our novel approach line-implicit LU-SGS which is four times faster than implicit LU-SGS and line-implicit Runge-Kutta. Implicit LU-SGS for Euler and line-implicit LU-SGS for Reynolds-averaged Navier-Stokes are at least twice faster than explicit and line-implicit Runge-Kutta, respectively, for 2D and 3D cases. For 3D Reynolds-averaged Navier-Stokes, multigrid did not accelerate the convergence and therefore may not be needed.

  1. Cough Is Dangerous: Neural Correlates of Implicit Body Symptoms Associations

    PubMed Central

    Mier, Daniela; Witthöft, Michael; Bailer, Josef; Ofer, Julia; Kerstner, Tobias; Rist, Fred; Diener, Carsten

    2016-01-01

    The negative interpretation of body sensations (e.g., as sign of a severe illness) is a crucial cognitive process in pathological health anxiety (HA). However, little is known about the nature and the degree of automaticity of this interpretation bias. We applied an implicit association test (IAT) in 20 subjects during functional magnetic resonance imaging (fMRI) to investigate behavioral and neural correlates of implicit attitudes toward symptom words. On the behavioral level, body symptom words elicited strong negative implicit association effects, as indexed by slowed reaction times, when symptom words were paired with the attribute “harmless” (incongruent condition). fMRI revealed increased activation in the dorsolateral prefrontal cortex (DLPFC) and posterior parietal cortex for the comparison of incongruent words with control words, as well as with a lower significance threshold also in comparison to congruent words. Moreover, activation in the DLPFC, posterior parietal cortex, nucleus accumbens, and cerebellum varied with individual levels of HA (again, in comparison to control words, as well as with a lower significance threshold also in comparison to congruent words). Slowed reaction times as well as increased activation in dorsolateral prefrontal and posterior parietal cortex point to increased inhibitory demands during the incongruent IAT condition. The positive association between HA severity and neural activity in nucleus accumbens, dorsolateral prefrontal, and posterior parietal cortex suggests that HA is characterized by both intensified negative implicit attitudes and hampered cognitive control mechanisms when confronted with body symptoms. PMID:26973558

  2. Genetic counselors’ implicit racial attitudes and their relationship to communication

    PubMed Central

    Schaa, Kendra L; Roter, Debra L; Biesecker, Barbara B; Cooper, Lisa A; Erby, Lori H

    2015-01-01

    Objective Implicit racial attitudes are thought to shape interpersonal interactions and may contribute to health care disparities. This study explored the relationship between genetic counselors’ implicit racial attitudes and their communication during simulated genetic counseling sessions. Methods A nationally representative sample of genetic counselors completed a web-based survey that included the Race Implicit Association Test (IAT). A subset of these counselors (n=67) had participated in an earlier study in which they were video recorded counseling Black, Hispanic and non-Hispanic White simulated clients (SC) about their prenatal or cancer risks. The counselors’ IAT scores were related to their session communication through robust regression modeling. Results Genetic counselors showed a moderate to strong pro-White bias on the Race IAT (M=0.41, SD=0.35). Counselors with stronger pro-White bias were rated as displaying lower levels of positive affect (p<.05) and tended to use less emotionally responsive communication (p<.10) when counseling minority SCs. When counseling White SCs, pro-White bias was associated with lower levels of verbal dominance during sessions (p<.10). Stronger pro-White bias was also associated with more positive ratings of counselors’ nonverbal effectiveness by White SCs. Conclusions Implicit racial bias is associated with negative markers of communication in minority client sessions and may contribute to racial disparities in processes of care related to genetic services. PMID:25622081

  3. Treating apraxia of speech with an implicit protocol that activates speech motor areas via inner speech

    PubMed Central

    Farias, Dana; Davis, Christine Herrick; Wilson, Stephen M

    2014-01-01

    Background Treatments of apraxia of speech (AOS) have traditionally relied on overt practice. One alternative to this method is implicit phoneme manipulation which was derived from early models on inner speech. Implicit phoneme manipulation requires the participant to covertly move and combine phonemes to form a new word. This process engages a system of self-monitoring which is referred to as fully conscious inner speech. Aims The present study aims to advance the understanding and validity of a new treatment for AOS, implicit phoneme manipulation. Tasks were designed to answer the following questions. 1. Would the practice of implicit phoneme manipulation improve the overt production of complex consonant blends in words? 2. Would this improvement generalize to untrained complex and simpler consonant blends in words? 3. Would these treatment tasks activate regions known to support motor planning and programming as verified by fMRI? Method & Procedures The participant was asked to covertly manipulate phonemes to create a new word and to associate this newly formed word to a target picture among 4 phonologically-related choices. To avoid overt practice, probes were collected only after each block of training was completed. Probe sessions assessed the effects of implicit practice on the overt production of simple and complex consonant blends in words. An imaging protocol compared semantic baseline tasks to treatment tasks to verify that implicit phoneme manipulation activated brain regions of interest. Outcomes & Results Behavioral: Response to implicit training of complex consonant blends resulted in improvements which were maintained 6 weeks after treatment. Further, this treatment generalized to simpler consonant blends in words. Imaging: Functional imaging during implicit phoneme manipulation showed significant activation in brain regions responsible for phonological processing when compared to the baseline semantic task. Conclusions Implicit phoneme manipulation

  4. AN INVESTIGATION OF IMPLICIT MEMORY THROUGH LEFT TEMPORAL LOBECTOMY FOR EPILEPSY

    PubMed Central

    Tracy, Joseph I.; Osipowicz, Karol; Godofsky, Samuel; Shah, Atif; Khan, Waseem; Sharan, Ashwini; Sperling, Michael R.

    2012-01-01

    Temporal lobe epilepsy patients have demonstrated a relative preservation in the integrity of implicit memory procedures. We examined performance in a verbal implicit and explicit memory task in left anterior temporal lobectomy patients (LATL) and healthy normal controls (NC) while undergoing fMRI. We hypothesized that despite the relative integrity of implicit memory in both the LATL patients and normal controls, the two groups would show distinct functional neuroanatomic profiles during implicit memory. LATLs and NCs performed Jacoby’s Process Dissociation Process (PDP) procedure during fMRI, requiring completion of word stems based on the previously studied words or new/unseen words. Measures of automaticity and recollection provided uncontaminated indices of implicit and explicit memory, respectively. The behavioral data showed that in the face of temporal lobe pathology implicit memory can be carried out, suggesting implicit verbal memory retrieval is non-mesial temporal in nature. Compared to NCs, the LATL patients showed reliable activation, not deactivation, during implicit (automatic) responding. The regions mediating this response were cortical (left medial frontal and precuneus) and striatal. The active regions in LATL patients have the capacity to implement associative, conditioned responses that might otherwise be carried out by a healthy temporal lobe, suggesting this represented a compensatory activity. Because the precuneus has also been implicated in explicit memory, the data suggests this structure may have a highly flexible functionality, capable of supporting implementation of either explicit memory, or automatic processes such as implicit memory retrieval. Our data suggest that a healthy mesial/anterior temporal lobe may be needed for generating the posterior deactivation perceptual priming response seen in normals. PMID:22981890

  5. Implicit Social Biases in People With Autism.

    PubMed

    Birmingham, Elina; Stanley, Damian; Nair, Remya; Adolphs, Ralph

    2015-11-01

    Implicit social biases are ubiquitous and are known to influence social behavior. A core diagnostic criterion of autism spectrum disorders (ASD) is abnormal social behavior. We investigated the extent to which individuals with ASD might show a specific attenuation of implicit social biases, using Implicit Association Tests (IATs) involving social (gender, race) and nonsocial (nature, shoes) categories. High-functioning adults with ASD showed intact but reduced IAT effects relative to healthy control participants. We observed no selective attenuation of implicit social (vs. nonsocial) biases in our ASD population. To extend these results, we supplemented our healthy control data with data collected from a large online sample from the general population and explored correlations between autistic traits and IAT effects. We observed no systematic relationship between autistic traits and implicit social biases in our online and control samples. Taken together, these results suggest that implicit social biases, as measured by the IAT, are largely intact in ASD. PMID:26386014

  6. Implicit Media Knowledge Experiments & Results

    NASA Astrophysics Data System (ADS)

    Ly, Muy-Chu; Germaneau, Alexis

    2011-08-01

    Implicit Media Knowledge aims to provide relevant information related to visual media without effort. It is based on the analysis of media usage from several users (e.g. a community). Algorithms based on clustering methods that extract relevant information (e.g. tags, taxonomy trees) related to a media from its usage are detailed. To validate our new approach, we propose to apply our concept and algorithms on a specific media use such as the analysis of how multiple users organize their media files. Significant results of two experiments will be highlighted. Perspectives of our work will be finally presented.

  7. Age Differences in Implicit Interference

    PubMed Central

    Ikier, Simay; Hasher, Lynn

    2006-01-01

    We assessed age differences in interference effects in priming by using fragment completion. In Experiment 1, noninterfering filler words preceded critical targets at study, and priming was age invariant. In Experiment 2, the same target items had interfering competitors at the beginning of the list, such that both the target and the competitor were legitimate solutions to a fragment. Having two responses to a cue was disruptive for older adults, but not for younger adults. Younger and older adults differ in their susceptibility to interference in implicit tasks, and interference may play a role in influencing the magnitude of age differences in priming. PMID:16960231

  8. An implicit Smooth Particle Hydrodynamic code

    SciTech Connect

    Charles E. Knapp

    2000-04-01

    An implicit version of the Smooth Particle Hydrodynamic (SPH) code SPHINX has been written and is working. In conjunction with the SPHINX code the new implicit code models fluids and solids under a wide range of conditions. SPH codes are Lagrangian, meshless and use particles to model the fluids and solids. The implicit code makes use of the Krylov iterative techniques for solving large linear-systems and a Newton-Raphson method for non-linear corrections. It uses numerical derivatives to construct the Jacobian matrix. It uses sparse techniques to save on memory storage and to reduce the amount of computation. It is believed that this is the first implicit SPH code to use Newton-Krylov techniques, and is also the first implicit SPH code to model solids. A description of SPH and the techniques used in the implicit code are presented. Then, the results of a number of tests cases are discussed, which include a shock tube problem, a Rayleigh-Taylor problem, a breaking dam problem, and a single jet of gas problem. The results are shown to be in very good agreement with analytic solutions, experimental results, and the explicit SPHINX code. In the case of the single jet of gas case it has been demonstrated that the implicit code can do a problem in much shorter time than the explicit code. The problem was, however, very unphysical, but it does demonstrate the potential of the implicit code. It is a first step toward a useful implicit SPH code.

  9. The "exaptation" of linguistic implicit strategies.

    PubMed

    Lombardi Vallauri, Edoardo

    2016-01-01

    Implicit strategies are known to increase persuasion performances. Implicits of content (vagueness, implicatures) and implicits of responsibility (presuppositions, topics) will be compared semiotically to non-linguistic implicits such as images and sounds. The results of psycholinguistic and neurolinguistic experiments will be used to propose that presuppositions and topics arose in language as means to spare addressees processing effort on already known contents, but they were subsequently "exapted" to spare effort on unknown marginal contents, and eventually to reduce the probability for doubtful contents to be processed thoroughly and rejected. This will be shown by many examples from commercial advertising and political propaganda. PMID:27478723

  10. The development of implicit gender attitudes.

    PubMed

    Dunham, Yarrow; Baron, Andrew Scott; Banaji, Mahzarin R

    2016-09-01

    The development course of implicit and explicit gender attitudes between the ages of 5 and adulthood is investigated. Findings demonstrate that implicit and explicit own-gender preferences emerge early in both boys and girls, but implicit own-gender preferences are stronger in young girls than boys. In addition, female participants' attitudes remain largely stable over development, whereas male participants' implicit and explicit attitudes show an age-related shift towards increasing female positivity. Gender attitudes are an anomaly in that social evaluations dissociate from social status, with both male and female participants tending to evaluate female more positively than male. PMID:26260250

  11. Implicit dose-response curves.

    PubMed

    Pérez Millán, Mercedes; Dickenstein, Alicia

    2015-06-01

    We develop tools from computational algebraic geometry for the study of steady state features of autonomous polynomial dynamical systems via elimination of variables. In particular, we obtain nontrivial bounds for the steady state concentration of a given species in biochemical reaction networks with mass-action kinetics. This species is understood as the output of the network and we thus bound the maximal response of the system. The improved bounds give smaller starting boxes to launch numerical methods. We apply our results to the sequential enzymatic network studied in Markevich et al. (J Cell Biol 164(3):353-359, 2004) to find nontrivial upper bounds for the different substrate concentrations at steady state. Our approach does not require any simulation, analytical expression to describe the output in terms of the input, or the absence of multistationarity. Instead, we show how to extract information from effectively computable implicit dose-response curves, with the use of resultants and discriminants. We moreover illustrate in the application to an enzymatic network, the relation between the exact implicit dose-response curve we obtain symbolically and the standard hysteresis diagram provided by a numerical ode solver. The setting and tools we propose could yield many other results adapted to any autonomous polynomial dynamical system, beyond those where it is possible to get explicit expressions. PMID:25008963

  12. Implicit Coupling Approach for Simulation of Charring Carbon Ablators

    NASA Technical Reports Server (NTRS)

    Chen, Yih-Kanq; Gokcen, Tahir

    2013-01-01

    This study demonstrates that coupling of a material thermal response code and a flow solver with nonequilibrium gas/surface interaction for simulation of charring carbon ablators can be performed using an implicit approach. The material thermal response code used in this study is the three-dimensional version of Fully Implicit Ablation and Thermal response program, which predicts charring material thermal response and shape change on hypersonic space vehicles. The flow code solves the reacting Navier-Stokes equations using Data Parallel Line Relaxation method. Coupling between the material response and flow codes is performed by solving the surface mass balance in flow solver and the surface energy balance in material response code. Thus, the material surface recession is predicted in flow code, and the surface temperature and pyrolysis gas injection rate are computed in material response code. It is demonstrated that the time-lagged explicit approach is sufficient for simulations at low surface heating conditions, in which the surface ablation rate is not a strong function of the surface temperature. At elevated surface heating conditions, the implicit approach has to be taken, because the carbon ablation rate becomes a stiff function of the surface temperature, and thus the explicit approach appears to be inappropriate resulting in severe numerical oscillations of predicted surface temperature. Implicit coupling for simulation of arc-jet models is performed, and the predictions are compared with measured data. Implicit coupling for trajectory based simulation of Stardust fore-body heat shield is also conducted. The predicted stagnation point total recession is compared with that predicted using the chemical equilibrium surface assumption

  13. Implicit memory effects when using pictures with children and adults: hypermnesia too?

    PubMed

    Landrum, R E

    1997-01-01

    Pictorial stimuli were used to investigate implicit- and explicit-memory phenomena in 3 experiments. The general procedure involved the presentation of a series of pictures during a study phase, followed by an implicit-memory test and an explicit-memory test. In the implicit-memory test, participants were presented with picture fragments and were instructed to write down what the fragment looked like. In the explicit-memory test, participants were asked to make a yes/no recognition decision regarding each picture. For children, implicit memory for pictures was robust when they were tested after a 48-hr interval, but that effect declined after 1 week; a similar implicit-memory effect for pictures was seen with college students; and the time course of the implicit-memory effect for pictures among college students (all short intervals of less than 1 week-1, 2, 3, 4, and 5 days) produced a more elevated implicit-memory performance than during the immediate testing condition. Hypermnesia may have been the cause of the increase in memory performance over the short intervals. PMID:9190048

  14. Using Implicit Measures to Highlight Science Teachers' Implicit Theories of Intelligence

    ERIC Educational Resources Information Center

    Mascret, Nicolas; Roussel, Peggy; Cury, François

    2015-01-01

    Using an innovative method, a Single-Target Implicit Association Test (ST-IAT) was created to explore the implicit theories of intelligence among science and liberal arts teachers and their relationships with their gender. The results showed that for science teachers--especially for male teachers--there was a negative implicit association between…

  15. Digital flight control design using implicit model following.

    NASA Technical Reports Server (NTRS)

    Stengel, R. F.

    1973-01-01

    A design procedure for determining the control gains of a discrete-time ('digital') control system is presented. The method is separable into four distinct steps: (1) the definition of closed-loop response criteria, (2) the choice of a discrete-time model which provides the desired response, (3) the determination of control gains which implicitly force the actual system to follow the desired response, and (4) the reduction of the measurement state by the introduction of an 'observer' (a form of integral-differential compensation). It is shown that a single desired response does not completely define the 'ideal' system. The response criterion generally leaves some parameters of the model unspecified, allowing two courses for improving the model: (1) definition of additional response criteria, or (2) redefinition of the discrete-time model for improved implicit model-following with the actual closed-loop system.

  16. New implicitly solvable potential produced by second order shape invariance

    SciTech Connect

    Cannata, F.; Ioffe, M.V.; Kolevatova, E.V.; Nishnianidze, D.N.

    2015-05-15

    The procedure proposed recently by Bougie et al. (2010) to study the general form of shape invariant potentials in one-dimensional Supersymmetric Quantum Mechanics (SUSY QM) is generalized to the case of Higher Order SUSY QM with supercharges of second order in momentum. A new shape invariant potential is constructed by this method. It is singular at the origin, it grows at infinity, and its spectrum depends on the choice of connection conditions in the singular point. The corresponding Schrödinger equation is solved explicitly: the wave functions are constructed analytically, and the energy spectrum is defined implicitly via the transcendental equation which involves Confluent Hypergeometric functions. - Highlights: • New potential with 2nd order irreducible shape invariance was constructed. • The connection conditions at the singularity of potential were obtained. • The explicit expressions for all wave functions were derived. • The implicit equation for the energy spectrum was obtained.

  17. Parallel Explicit and Implicit Control of Reaching

    PubMed Central

    Mazzoni, Pietro; Wexler, Nancy S.

    2009-01-01

    Background Human movement can be guided automatically (implicit control) or attentively (explicit control). Explicit control may be engaged when learning a new movement, while implicit control enables simultaneous execution of multiple actions. Explicit and implicit control can often be assigned arbitrarily: we can simultaneously drive a car and tune the radio, seamlessly allocating implicit or explicit control to either action. This flexibility suggests that sensorimotor signals, including those that encode spatially overlapping perception and behavior, can be accurately segregated to explicit and implicit control processes. Methodology/Principal Findings We tested human subjects' ability to segregate sensorimotor signals to parallel control processes by requiring dual (explicit and implicit) control of the same reaching movement and testing for interference between these processes. Healthy control subjects were able to engage dual explicit and implicit motor control without degradation of performance compared to explicit or implicit control alone. We then asked whether segregation of explicit and implicit motor control can be selectively disrupted by studying dual-control performance in subjects with no clinically manifest neurologic deficits in the presymptomatic stage of Huntington's disease (HD). These subjects performed successfully under either explicit or implicit control alone, but were impaired in the dual-control condition. Conclusion/Significance The human nervous system can exert dual control on a single action, and is therefore able to accurately segregate sensorimotor signals to explicit and implicit control. The impairment observed in the presymptomatic stage of HD points to a possible crucial contribution of the striatum to the segregation of sensorimotor signals to multiple control processes. PMID:19847295

  18. Implicit and Explicit Instruction of Spelling Rules

    ERIC Educational Resources Information Center

    Kemper, M. J.; Verhoeven, L.; Bosman, A. M. T.

    2012-01-01

    The study aimed to compare the differential effectiveness of explicit and implicit instruction of two Dutch spelling rules. Students with and without spelling disabilities were instructed a spelling rule either implicitly or explicitly in two experiments. Effects were tested in a pretest-intervention-posttest control group design. Experiment 1…

  19. Evidence for Implicit Learning in Syntactic Comprehension

    ERIC Educational Resources Information Center

    Fine, Alex B.; Jaeger, T. Florian

    2013-01-01

    This study provides evidence for implicit learning in syntactic comprehension. By reanalyzing data from a syntactic priming experiment (Thothathiri & Snedeker, 2008), we find that the error signal associated with a syntactic prime influences comprehenders' subsequent syntactic expectations. This follows directly from error-based implicit learning…

  20. Understanding Implicit Bias: What Educators Should Know

    ERIC Educational Resources Information Center

    Staats, Cheryl

    2016-01-01

    The desire to ensure the best for children is precisely why educators should become aware of the concept of implicit bias: the attitudes or stereotypes that affect our understanding, actions, and decisions in an unconscious manner. Operating outside of our conscious awareness, implicit biases are pervasive, and they can challenge even the most…

  1. Implicit and Explicit Exercise and Sedentary Identity

    ERIC Educational Resources Information Center

    Berry, Tanya R.; Strachan, Shaelyn M.

    2012-01-01

    We examined the relationship between implicit and explicit "exerciser" and "sedentary" self-identity when activated by stereotypes. Undergraduate participants (N = 141) wrote essays about university students who either liked to exercise or engage in sedentary activities. This was followed by an implicit identity task and an explicit measure of…

  2. Implicit and Explicit Learning of Languages.

    ERIC Educational Resources Information Center

    McDermott, James E.

    1999-01-01

    Discusses theoretical and practical issues connected with implicit and explicit learning of languages. Explicit learning is knowledge expressed in the form of rules or definitions; implicit knowledge can be inferred to exist because of observed performance but cannot be clearly described. Hypothesizes why explicit learning can lead to implicit…

  3. Altered Implicit Category Learning in Anorexia Nervosa

    PubMed Central

    Shott, Megan E.; Filoteo, J. Vincent; Jappe, Leah M.; Pryor, Tamara; Maddox, W. Todd; Rollin, Michael D.H.; Hagman, Jennifer O.; Frank, Guido K.W.

    2012-01-01

    Objective Recent research has identified specific cognitive deficits in patients with anorexia nervosa (AN), including impairment in executive functioning and attention. Another such cognitive process, implicit category learning has been less studied in AN. This study examined whether implicit category learning is impaired in AN. Method Twenty-one women diagnosed with AN and 19 control women (CW) were administered an implicit category learning task in which they were asked to categorize simple perceptual stimuli (Gabor patches) into one of two categories. Category membership was based on a linear integration (i.e., an implicit task) of two stimulus dimensions (orientation and spatial frequency of the stimulus). Results AN individuals were less accurate on implicit category learning relative to age-matched CW. Model-based analyses indicated that, even when AN individuals used the appropriate (i.e., implicit) strategy they were still impaired relative to CW who also used the same strategy. In addition, task performance in AN patients was worse the higher they were in self-reported novelty seeking and the lower they were in sensitivity to punishment. Conclusions These results indicate that AN patients have implicit category learning deficits, and given this type of learning is thought to be mediated by striatal dopamine pathways, AN patients may have deficits in these neural systems. The finding of significant correlations with novelty seeking and sensitivity to punishment suggests that feedback sensitivity is related to implicit learning in AN. PMID:22201300

  4. Psychometric Intelligence Dissociates Implicit and Explicit Learning

    ERIC Educational Resources Information Center

    Gebauer, Guido F.; Mackintosh, Nicholas J.

    2007-01-01

    The hypothesis that performance on implicit learning tasks is unrelated to psychometric intelligence was examined in a sample of 605 German pupils. Performance in artificial grammar learning, process control, and serial learning did not correlate with various measures of intelligence when participants were given standard implicit instructions.…

  5. Toward textbook multigrid efficiency for fully implicit resistive magnetohydrodynamics

    SciTech Connect

    Adams, Mark F.; Samtaney, Ravi; Brandt, Achi

    2010-09-01

    Multigrid methods can solve some classes of elliptic and parabolic equations to accuracy below the truncation error with a work-cost equivalent to a few residual calculations – so-called ‘‘textbook” multigrid efficiency. We investigate methods to solve the system of equations that arise in time dependent magnetohydrodynamics (MHD) simulations with textbook multigrid efficiency. We apply multigrid techniques such as geometric interpolation, full approximate storage, Gauss–Seidel smoothers, and defect correction for fully implicit, nonlinear, second-order finite volume discretizations of MHD. We apply these methods to a standard resistive MHD benchmark problem, the GEM reconnection problem, and add a strong magnetic guide field, which is a critical characteristic of magnetically confined fusion plasmas. We show that our multigrid methods can achieve near textbook efficiency on fully implicit resistive MHD simulations.

  6. Toward textbook multigrid efficiency for fully implicit resistive magnetohydrodynamics

    SciTech Connect

    Adams, Mark F.; Samtaney, Ravi; Brandt, Achi

    2010-09-01

    Multigrid methods can solve some classes of elliptic and parabolic equations to accuracy below the truncation error with a work-cost equivalent to a few residual calculations - so-called 'textbook' multigrid efficiency. We investigate methods to solve the system of equations that arise in time dependent magnetohydrodynamics (MHD) simulations with textbook multigrid efficiency. We apply multigrid techniques such as geometric interpolation, full approximate storage, Gauss-Seidel smoothers, and defect correction for fully implicit, nonlinear, second-order finite volume discretizations of MHD. We apply these methods to a standard resistive MHD benchmark problem, the GEM reconnection problem, and add a strong magnetic guide field, which is a critical characteristic of magnetically confined fusion plasmas. We show that our multigrid methods can achieve near textbook efficiency on fully implicit resistive MHD simulations.

  7. Toward textbook multigrid efficiency for fully implicit resistive magnetohydrodynamics

    SciTech Connect

    Adams, Mark F.; Samtaney, Ravi; Brandt, Achi

    2013-12-14

    Multigrid methods can solve some classes of elliptic and parabolic equations to accuracy below the truncation error with a work-cost equivalent to a few residual calculations – so-called “textbook” multigrid efficiency. We investigate methods to solve the system of equations that arise in time dependent magnetohydrodynamics (MHD) simulations with textbook multigrid efficiency. We apply multigrid techniques such as geometric interpolation, full approximate storage, Gauss-Seidel smoothers, and defect correction for fully implicit, nonlinear, second-order finite volume discretizations of MHD. We apply these methods to a standard resistive MHD benchmark problem, the GEM reconnection problem, and add a strong magnetic guide field, which is a critical characteristic of magnetically confined fusion plasmas. We show that our multigrid methods can achieve near textbook efficiency on fully implicit resistive MHD simulations.

  8. Toward textbook multigrid efficiency for fully implicit resistive magnetohydrodynamics

    DOE PAGESBeta

    Adams, Mark F.; Samtaney, Ravi; Brandt, Achi

    2010-09-01

    Multigrid methods can solve some classes of elliptic and parabolic equations to accuracy below the truncation error with a work-cost equivalent to a few residual calculations – so-called ‘‘textbook” multigrid efficiency. We investigate methods to solve the system of equations that arise in time dependent magnetohydrodynamics (MHD) simulations with textbook multigrid efficiency. We apply multigrid techniques such as geometric interpolation, full approximate storage, Gauss–Seidel smoothers, and defect correction for fully implicit, nonlinear, second-order finite volume discretizations of MHD. We apply these methods to a standard resistive MHD benchmark problem, the GEM reconnection problem, and add a strong magnetic guide field,more » which is a critical characteristic of magnetically confined fusion plasmas. We show that our multigrid methods can achieve near textbook efficiency on fully implicit resistive MHD simulations.« less

  9. Implicit solvers for unstructured meshes

    NASA Technical Reports Server (NTRS)

    Venkatakrishnan, V.; Mavriplis, Dimitri J.

    1991-01-01

    Implicit methods were developed and tested for unstructured mesh computations. The approximate system which arises from the Newton linearization of the nonlinear evolution operator is solved by using the preconditioned GMRES (Generalized Minimum Residual) technique. Three different preconditioners were studied, namely, the incomplete LU factorization (ILU), block diagonal factorization, and the symmetric successive over relaxation (SSOR). The preconditioners were optimized to have good vectorization properties. SSOR and ILU were also studied as iterative schemes. The various methods are compared over a wide range of problems. Ordering of the unknowns, which affects the convergence of these sparse matrix iterative methods, is also studied. Results are presented for inviscid and turbulent viscous calculations on single and multielement airfoil configurations using globally and adaptively generated meshes.

  10. Implicit restart Lanczos as an eigensolver

    NASA Astrophysics Data System (ADS)

    Rajaie Khorasani, Reza; Dumont, Randall S.

    2009-03-01

    This paper investigates the efficiency of the implicit restart Lanczos and simple (without reorthogonalization) Lanczos algorithms, as eigensolvers for large scale computations in molecular and chemical physics. Using the cardioid billiard and the hydrogen cyanide/hydrogen isocyanide (HCN/HNC) molecule as model systems we demonstrate superior efficiency of implicit restart Lanczos compared to the simple Lanczos algorithm. A modified implementation of implicit restart Lanczos is also presented which works with a smaller Krylov space—with associated savings in memory—and can handle larger basis sets than the usual implicit restart Lanczos. It also enables getting all eigenpairs of a matrix, or all eigenvalues below a threshold (where the number of such is not known before hand), which is more difficult with the usual implicit restart algorithm.

  11. Implicit restart Lanczos as an eigensolver.

    PubMed

    Rajaie Khorasani, Reza; Dumont, Randall S

    2009-03-01

    This paper investigates the efficiency of the implicit restart Lanczos and simple (without reorthogonalization) Lanczos algorithms, as eigensolvers for large scale computations in molecular and chemical physics. Using the cardioid billiard and the hydrogen cyanide/hydrogen isocyanide (HCN/HNC) molecule as model systems we demonstrate superior efficiency of implicit restart Lanczos compared to the simple Lanczos algorithm. A modified implementation of implicit restart Lanczos is also presented which works with a smaller Krylov space-with associated savings in memory-and can handle larger basis sets than the usual implicit restart Lanczos. It also enables getting all eigenpairs of a matrix, or all eigenvalues below a threshold (where the number of such is not known before hand), which is more difficult with the usual implicit restart algorithm. PMID:19392082

  12. Implicit social cognition: From measures to mechanisms

    PubMed Central

    Nosek, Brian A.; Hawkins, Carlee Beth; Frazier, Rebecca S.

    2011-01-01

    Most of human cognition occurs outside of conscious awareness or conscious control. Some of these implicit processes influence social perception, judgment and action. The last fifteen years of research in implicit social cognition can be characterized as the Age of Measurement because of a proliferation of measurement methods and research evidence demonstrating their practical value for predicting human behavior. Implicit measures assess constructs that are distinct, but related, to self-report assessments, and predict variation in behavior that is not accounted for by those explicit measures. The present state of knowledge provides a foundation for the next age of implicit social cognition – clarification of the mechanisms underlying implicit measurement and how the measured constructs influence behavior. PMID:21376657

  13. Hooked on a feeling: affective anti-smoking messages are more effective than cognitive messages at changing implicit evaluations of smoking

    PubMed Central

    Smith, Colin Tucker; De Houwer, Jan

    2015-01-01

    Because implicit evaluations are thought to underlie many aspects of behavior, researchers have started looking for ways to change them. We examine whether and when persuasive messages alter strongly held implicit evaluations of smoking. In smokers, an affective anti-smoking message led to more negative implicit evaluations on four different implicit measures as compared to a cognitive anti-smoking message which seemed to backfire. Additional analyses suggested that the observed effects were mediated by the feelings and emotions raised by the messages. In non-smokers, both the affective and cognitive message engendered slightly more negative implicit evaluations. We conclude that persuasive messages change implicit evaluations in a way that depends on properties of the message and of the participant. Thus, our data open new avenues for research directed at tailoring persuasive messages to change implicit evaluations. PMID:26557099

  14. Intact implicit processing of facial threat cues in schizophrenia.

    PubMed

    Shasteen, Jonathon R; Pinkham, Amy E; Kelsven, Skylar; Ludwig, Kelsey; Payne, B Keith; Penn, David L

    2016-01-01

    An emerging body of research suggests that people with schizophrenia retain the ability to implicitly perceive facial affect, despite well-documented difficulty explicitly identifying emotional expressions. It remains unclear, however, whether such functional implicit processing extends beyond emotion to other socially relevant facial cues. Here, we constructed two novel versions of the Affect Misattribution Procedure, a paradigm in which affective responses to primes are projected onto neutral targets. The first version included three face primes previously validated to elicit varying inferences of threat from healthy individuals via emotion-independent structural modification (e.g., nose and eye size). The second version included the threat-relevant emotional primes of angry, neutral, and happy faces. Data from 126 participants with schizophrenia and 84 healthy controls revealed that although performing more poorly on an assessment of explicit emotion recognition, patients showed normative implicit threat processing for both non-emotional and emotional facial cues. Collectively, these results support recent hypotheses postulating that the initial perception of salient facial information remains intact in schizophrenia, but that deficits arise at subsequent stages of contextual integration and appraisal. Such a breakdown in the stream of face processing has important implications for mechanistic models of social cognitive impairment in schizophrenia and treatment strategies aiming to improve functional outcome. PMID:26673971

  15. Haptics-based dynamic implicit solid modeling.

    PubMed

    Hua, Jing; Qin, Hong

    2004-01-01

    This paper systematically presents a novel, interactive solid modeling framework, Haptics-based Dynamic Implicit Solid Modeling, which is founded upon volumetric implicit functions and powerful physics-based modeling. In particular, we augment our modeling framework with a haptic mechanism in order to take advantage of additional realism associated with a 3D haptic interface. Our dynamic implicit solids are semi-algebraic sets of volumetric implicit functions and are governed by the principles of dynamics, hence responding to sculpting forces in a natural and predictable manner. In order to directly manipulate existing volumetric data sets as well as point clouds, we develop a hierarchical fitting algorithm to reconstruct and represent discrete data sets using our continuous implicit functions, which permit users to further design and edit those existing 3D models in real-time using a large variety of haptic and geometric toolkits, and visualize their interactive deformation at arbitrary resolution. The additional geometric and physical constraints afford more sophisticated control of the dynamic implicit solids. The versatility of our dynamic implicit modeling enables the user to easily modify both the geometry and the topology of modeled objects, while the inherent physical properties can offer an intuitive haptic interface for direct manipulation with force feedback. PMID:15794139

  16. Cognitive control: a role for implicit learning?

    PubMed

    Deroost, Natacha; Vandenbossche, Jochen; Zeischka, Peter; Coomans, Daphné; Soetens, Eric

    2012-09-01

    We investigated the influence of implicit learning on cognitive control. In a sequential Stroop task, participants implicitly learned a sequence placed on the color of the Stroop words. In Experiment 1, Stroop conflict was lower in sequenced than in random trials (learning-improved control). However, as these results were derived from an interaction between learning and conflict, they could also be explained by improved implicit learning (difference between random and sequenced trials), under incongruent compared with congruent trials (control-improved learning). Therefore, we further unraveled the direction of the interaction in 2 additional experiments. In Experiment 2, participants who learned the color sequence were no better at resolving conflict than participants who did not undergo sequence training. This shows that implicit knowledge does not directly reduce conflict (no learning-improved control). In Experiment 3, the amount of conflict did not directly improve learning either (no control-improved learning). However, conflict had a significant impact on the expression of implicit learning, as most knowledge was expressed under the highest amount of conflict. Thus, task-optimization was accomplished by an increased reliance on implicit sequence knowledge under high conflict. These findings demonstrate that implicit learning processes can be flexibly recruited to support cognitive control functions. PMID:22428719

  17. Strong Interaction

    SciTech Connect

    Karsch, F.; Vogelsang, V.

    2009-09-29

    We will give here an overview of our theory of the strong interactions, Quantum Chromo Dynamics (QCD) and its properties. We will also briefly review the history of the study of the strong interactions, and the discoveries that ultimately led to the formulation of QCD. The strong force is one of the four known fundamental forces in nature, the others being the electromagnetic, the weak and the gravitational force. The strong force, usually referred to by scientists as the 'strong interaction', is relevant at the subatomic level, where it is responsible for the binding of protons and neutrons to atomic nuclei. To do this, it must overcome the electric repulsion between the protons in an atomic nucleus and be the most powerful force over distances of a few fm (1fm=1 femtometer=1 fermi=10{sup -15}m), the typical size of a nucleus. This property gave the strong force its name.

  18. Evidence for implicit learning in syntactic comprehension.

    PubMed

    Fine, Alex B; Florian Jaeger, T

    2013-04-01

    This study provides evidence for implicit learning in syntactic comprehension. By reanalyzing data from a syntactic priming experiment (Thothathiri & Snedeker, 2008), we find that the error signal associated with a syntactic prime influences comprehenders' subsequent syntactic expectations. This follows directly from error-based implicit learning accounts of syntactic priming, but it is unexpected under accounts that consider syntactic priming a consequence of temporary increases in base-level activation. More generally, the results raise questions about the principles underlying the maintenance of implicit statistical knowledge relevant to language processing, and about possible functional motivations for syntactic priming. PMID:23363004

  19. GroPBS: Fast Solver for Implicit Electrostatics of Biomolecules

    PubMed Central

    Bertelshofer, Franziska; Sun, Liping; Greiner, Günther; Böckmann, Rainer A.

    2015-01-01

    Knowledge about the electrostatic potential on the surface of biomolecules or biomembranes under physiological conditions is an important step in the attempt to characterize the physico-chemical properties of these molecules and, in particular, also their interactions with each other. Additionally, knowledge about solution electrostatics may also guide the design of molecules with specified properties. However, explicit water models come at a high computational cost, rendering them unsuitable for large design studies or for docking purposes. Implicit models with the water phase treated as a continuum require the numerical solution of the Poisson–Boltzmann equation (PBE). Here, we present a new flexible program for the numerical solution of the PBE, allowing for different geometries, and the explicit and implicit inclusion of membranes. It involves a discretization of space and the computation of the molecular surface. The PBE is solved using finite differences, the resulting set of equations is solved using a Gauss–Seidel method. It is shown for the example of the sucrose transporter ScrY that the implicit inclusion of a surrounding membrane has a strong effect also on the electrostatics within the pore region and, thus, needs to be carefully considered, e.g., in design studies on membrane proteins. PMID:26636074

  20. Developmental dissociation between the maturation of procedural memory and declarative memory.

    PubMed

    Finn, Amy S; Kalra, Priya B; Goetz, Calvin; Leonard, Julia A; Sheridan, Margaret A; Gabrieli, John D E

    2016-02-01

    Declarative memory and procedural memory are known to be two fundamentally different kinds of memory that are dissociable in their psychological characteristics and measurement (explicit vs. implicit) and in the neural systems that subserve each kind of memory. Declarative memory abilities are known to improve from childhood through young adulthood, but the developmental maturation of procedural memory is largely unknown. We compared 10-year-old children and young adults on measures of declarative memory and working memory capacity and on four measures of procedural memory that have been strongly dissociated from declarative memory (mirror tracing, rotary pursuit, probabilistic classification, and artificial grammar). Children had lesser declarative memory ability and lesser working memory capacity than adults, but children exhibited learning equivalent to adults on all four measures of procedural memory. Therefore, declarative memory and procedural memory are developmentally dissociable, with procedural memory being adult-like by age 10years and declarative memory continuing to mature into young adulthood. PMID:26560675

  1. Implicit collaboration of sensor systems

    NASA Astrophysics Data System (ADS)

    Hintz, Kenneth J.

    2004-08-01

    The concept of goal lattices for the evaluation of potential sensor actions can be used to cause a multiplicity of heterogeneous sensor systems to collaborate. Previously goal lattices have been used to compute the value to a sensor system of taking a particular action in terms of how well that action contributes to the accomplishment of the topmost goals. This assumes that each sensor system is autonomous and only responsible to itself. If the topmost goals of each sensor system's goal lattice has adjoined to it two additional goals, namely "collaboration" and "altruism", then the value system is extended to include servicing requests from other systems. Two aircraft on a common mission can each benefit from measurements taken by the other aircraft either to confirm their own measurements, to create a pseudo-sensor, or to extend the area of coverage. The altruism goal indicates how much weight a sensor management system (SMS) will give in responding to a measurement request from any other system. The collaboration goal indicates how much weight will be given to responding to a measurement request from specific systems which are defined as being part of a collaborating group. By varying the values of the altruism and collaboration goals of each system, either locally or globally, various levels of implicit cooperation among sensor systems can be caused to emerge.

  2. Variational data assimilation with a semi-Lagrangian semi-implicit global shallow-water equation model and its adjoint

    NASA Technical Reports Server (NTRS)

    Li, Y.; Navon, I. M.; Courtier, P.; Gauthier, P.

    1993-01-01

    An adjoint model is developed for variational data assimilation using the 2D semi-Lagrangian semi-implicit (SLSI) shallow-water equation global model of Bates et al. with special attention being paid to the linearization of the interpolation routines. It is demonstrated that with larger time steps the limit of the validity of the tangent linear model will be curtailed due to the interpolations, especially in regions where sharp gradients in the interpolated variables coupled with strong advective wind occur, a synoptic situation common in the high latitudes. This effect is particularly evident near the pole in the Northern Hemisphere during the winter season. Variational data assimilation experiments of 'identical twin' type with observations available only at the end of the assimilation period perform well with this adjoint model. It is confirmed that the computational efficiency of the semi-Lagrangian scheme is preserved during the minimization process, related to the variational data assimilation procedure.

  3. Lay dispositionism and implicit theories of personality.

    PubMed

    Chiu, C Y; Hong, Y Y; Dweck, C S

    1997-07-01

    Lay dispositionism refers to lay people's tendency to use traits as the basic unit of analysis in social perception (L. Ross & R. E. Nisbett, 1991). Five studies explored the relation between the practices indicative of lay dispositionism and people's implicit theories about the nature of personal attributes. As predicted, compared with those who believed that personal attributes are malleable (incremental theorists), those who believed in fixed traits (entity theorists) used traits or trait-relevant information to make stronger future behavioral predictions (Studies 1 and 2) and made stronger trait inferences from behavior (Study 3). Moreover, the relation between implicit theories and lay dispositionism was found in both the United States (a more individualistic culture) and Hong Kong (a more collectivistic culture), suggesting this relation to be generalizable across cultures (Study 4). Finally, an experiment in which implicit theories were manipulated provided preliminary evidence for the possible causal role of implicit theories in lay dispositionism (Study 5). PMID:9216077

  4. Parallelizing alternating direction implicit solver on GPUs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We present a parallel Alternating Direction Implicit (ADI) solver on GPUs. Our implementation significantly improves existing implementations in two aspects. First, we address the scalability issue of existing Parallel Cyclic Reduction (PCR) implementations by eliminating their hardware resource con...

  5. Implicit learning and acquisition of music.

    PubMed

    Rohrmeier, Martin; Rebuschat, Patrick

    2012-10-01

    Implicit learning is a core process for the acquisition of a complex, rule-based environment from mere interaction, such as motor action, skill acquisition, or language. A body of evidence suggests that implicit knowledge governs music acquisition and perception in nonmusicians and musicians, and that both expert and nonexpert participants acquire complex melodic, harmonic, and other features from mere exposure. While current findings and computational modeling largely support the learning of chunks, some results indicate learning of more complex structures. Despite the body of evidence, more research is required to support the cross-cultural validity of implicit learning and to show that core and more complex music theoretical features are acquired implicitly. PMID:23060126

  6. Implicit Learning of Written Regularities and Its Relation to Literacy Acquisition in a Shallow Orthography.

    PubMed

    Nigro, Luciana; Jiménez-Fernández, Gracia; Simpson, Ian C; Defior, Sylvia

    2015-10-01

    Some research on literacy acquisition suggests that implicit learning processes may be related to reading and writing proficiency in English, which is a deep orthography. However, little research has been done to determine if the same is true in shallow orthographies. Here, we investigated whether the implicit learning ability of third grade Spanish speaking children was related to their reading and writing abilities. Twenty eight children viewed pseudowords which all adhered to untaught graphotactic rules and were later assessed to determine their implicit learning of these rules. The children's reading and writing abilities were also assessed using standardized tests. No correlations were found between the participants' level of implicit learning and their performance on reading tasks or on a pseudoword writing task, suggesting that implicit learning is not strongly related to the acquisition of phonological regularities in a shallow orthography. A correlation was found between recognition of previously seen exemplars and the ability to spell inconsistent words which require word specific knowledge to resolve the spelling inconsistencies. This result suggests that implicit learning mechanisms may play a role in the acquisition of lexical knowledge and thus, in writing proficiency. PMID:24935792

  7. Predictive models of implicit and explicit attitudes.

    PubMed

    Perugini, Marco

    2005-03-01

    Explicit attitudes have long been assumed to be central factors influencing behaviour. A recent stream of studies has shown that implicit attitudes, typically measured with the Implicit Association Test (IAT), can also predict a significant range of behaviours. This contribution is focused on testing different predictive models of implicit and explicit attitudes. In particular, three main models can be derived from the literature: (a) additive (the two types of attitudes explain different portion of variance in the criterion), (b) double dissociation (implicit attitudes predict spontaneous whereas explicit attitudes predict deliberative behaviour), and (c) multiplicative (implicit and explicit attitudes interact in influencing behaviour). This paper reports two studies testing these models. The first study (N = 48) is about smoking behaviour, whereas the second study (N = 109) is about preferences for snacks versus fruit. In the first study, the multiplicative model is supported, whereas the double dissociation model is supported in the second study. The results are discussed in light of the importance of focusing on different patterns of prediction when investigating the directive influence of implicit and explicit attitudes on behaviours. PMID:15901390

  8. An implicit sampling theorem for bounded bandlimited functions

    NASA Technical Reports Server (NTRS)

    Bar-David, I.

    1974-01-01

    A rigorous proof of the 'strong bias tone' scheme is embodied in the implicit sampling theorem. The representation of signals that are sample functions of possible nonstationary random processes being of principal interest, the proof could not directly invoke results from classical analysis, which depend on the existence of the Fourier transform of the function under consideration; rather, it is based on Zakai's (1965) theorem on the series expansion of functions, band-limited under a suitably extended definition. A practical circuit that restores an approximate version of the signal from its sine-wave-crossings is presented and possible improvements to it are discussed.

  9. Gifted Students' Implicit Beliefs about Intelligence and Giftedness

    ERIC Educational Resources Information Center

    Makel, Matthew C.; Snyder, Kate E.; Thomas, Chandler; Malone, Patrick S.; Putallaz, Martha

    2015-01-01

    Growing attention is being paid to individuals' implicit beliefs about the nature of intelligence. However, implicit beliefs about giftedness are currently underexamined. In the current study, we examined academically gifted adolescents' implicit beliefs about both intelligence and giftedness. Overall, participants' implicit beliefs about…

  10. Implicit Association Tests of Attitudes toward Persons with Disabilities

    ERIC Educational Resources Information Center

    Thomas, Adrian; Vaughn, Edwin D.; Doyle, Andrea; Bubb, Robert

    2014-01-01

    The authors assessed 3 of the currently available implicit association tests designed to measure attitudes toward persons with disabilities. The Revised Multiple Disability Implicit Association Test, the Implicit Association Test for Attitudes Toward Athletes With Disabilities, and the Disability Attitude Implicit Association Test were related to…

  11. Implicit solution of large-scale radiation diffusion problems

    SciTech Connect

    Brown, P N; Graziani, F; Otero, I; Woodward, C S

    2001-01-04

    In this paper, we present an efficient solution approach for fully implicit, large-scale, nonlinear radiation diffusion problems. The fully implicit approach is compared to a semi-implicit solution method. Accuracy and efficiency are shown to be better for the fully implicit method on both one- and three-dimensional problems with tabular opacities taken from the LEOS opacity library.

  12. The AGBNP2 Implicit Solvation Model

    PubMed Central

    Gallicchio, Emilio; Paris, Kristina; Levy, Ronald M.

    2009-01-01

    The AGBNP2 implicit solvent model, an evolution of the Analytical Generalized Born plus Non-Polar (AGBNP) model we have previously reported, is presented with the aim of modeling hydration effects beyond those described by conventional continuum dielectric representations. A new empirical hydration free energy component based on a procedure to locate and score hydration sites on the solute surface is introduced to model first solvation shell effects, such as hydrogen bonding, which are poorly described by continuum dielectric models. This new component is added to the Generalized Born and non-polar AGBNP terms. Also newly introduced is an analytical Solvent Excluded Volume (SEV) model which improves the solute volume description by reducing the effect of spurious high-dielectric interstitial spaces present in conventional van der Waals representations. The AGBNP2 model is parametrized and tested with respect to experimental hydration free energies of small molecules and the results of explicit solvent simulations. Modeling the granularity of water is one of the main design principles employed for the the first shell solvation function and the SEV model, by requiring that water locations have a minimum available volume based on the size of a water molecule. It is shown that the new volumetric model produces Born radii and surface areas in good agreement with accurate numerical evaluations of these quantities. The results of molecular dynamics simulations of a series of mini-proteins show that the new model produces conformational ensembles in substantially better agreement with reference explicit solvent ensembles than the original AGBNP model with respect to both structural and energetics measures. PMID:20419084

  13. The Multiple Disability Implicit Association Test: Psychometric Analysis of a Multiple Administration IAT Measure

    ERIC Educational Resources Information Center

    Vaughn, E. Daly; Thomas, Adrian; Doyle, Andrea L.

    2011-01-01

    The authors report the psychometric properties of the "Multiple Disability Implicit Association Test" (MDIAT) using the updated implementation procedure and scoring algorithm provided by Greenwald and colleagues. Undergraduate students (N = 249) completed the four disability condition IATs composing the MDIAT in addition to several self-report…

  14. Is Implicit Sequence Learning Impaired in Schizophrenia? A Meta-Analysis

    ERIC Educational Resources Information Center

    Siegert, Richard J.; Weatherall, Mark; Bell, Elliot M.

    2008-01-01

    Cognition in schizophrenia seems to be characterized by impaired performance on most tests of explicit or declarative learning contrasting with relatively intact performance on most tests of implicit or procedural learning. At the same time there have been conflicting results for studies that have used the Serial Reaction Time (SRT) task to…

  15. The Explicit/Implicit Knowledge Distinction and Working Memory: Implications for Second-Language Reading Comprehension

    ERIC Educational Resources Information Center

    Ercetin, Gulcan; Alptekin, Cem

    2013-01-01

    Following an extensive overview of the subject, this study explores the relationships between second-language (L2) explicit/implicit knowledge sources, embedded in the declarative/procedural memory systems, and L2 working memory (WM) capacity. It further examines the relationships between L2 reading comprehension and L2 WM capacity as well as…

  16. Forming implicit and explicit attitudes toward individuals: social group association cues.

    PubMed

    McConnell, Allen R; Rydell, Robert J; Strain, Laura M; Mackie, Diane M

    2008-05-01

    The authors explored how social group cues (e.g., obesity, physical attractiveness) strongly associated with valence affect the formation of attitudes toward individuals. Although explicit attitude formation has been examined in much past research (e.g., S. T. Fiske & S. L. Neuberg, 1990), in the current work, the authors considered how implicit as well as explicit attitudes toward individuals are influenced by these cues. On the basis of a systems of evaluation perspective (e.g., R. J. Rydell & A. R. McConnell, 2006; R. J. Rydell, A. R. McConnell, D. M. Mackie, & L. M. Strain, 2006), the authors anticipated and found that social group cues had a strong impact on implicit attitude formation in all cases and on explicit attitude formation when behavioral information about the target was ambiguous. These findings obtained for cues related to obesity (Experiments 1 and 4) and physical attractiveness (Experiment 2). In Experiment 3, parallel findings were observed for race, and participants holding greater implicit racial prejudice against African Americans formed more negative implicit attitudes toward a novel African American target person than did participants with less implicit racial prejudice. Implications for research on attitudes, impression formation, and stigma are discussed. PMID:18444739

  17. Multigrid solution for the compressible Euler equations by an implicit characteristic-flux-averaging

    NASA Astrophysics Data System (ADS)

    Kanarachos, A.; Vournas, I.

    A formulation of an implicit characteristic-flux-averaging method for the compressible Euler equations combined with the multigrid method is presented. The method is based on correction scheme and implicit Gudunov type finite volume scheme and is applied to two dimensional cases. Its principal feature is an averaging procedure based on the eigenvalue analysis of the Euler equations by means of which the fluxes are evaluated at the finite volume faces. The performance of the method is demonstrated for different flow problems around RAE-2922 and NACA-0012 airfoils and an internal flow over a circular arc.

  18. On the accuracy and convergence of implicit numerical integration of finite element generated ordinary differential equations

    NASA Technical Reports Server (NTRS)

    Baker, A. J.; Soliman, M. O.

    1978-01-01

    A study of accuracy and convergence of linear functional finite element solution to linear parabolic and hyperbolic partial differential equations is presented. A variable-implicit integration procedure is employed for the resultant system of ordinary differential equations. Accuracy and convergence is compared for the consistent and two lumped assembly procedures for the identified initial-value matrix structure. Truncation error estimation is accomplished using Richardson extrapolation.

  19. How Explicit and Implicit Test Instructions in an Implicit Learning Task Affect Performance

    PubMed Central

    Witt, Arnaud; Puspitawati, Ira; Vinter, Annie

    2013-01-01

    Typically developing children aged 5 to 8 years were exposed to artificial grammar learning. Following an implicit exposure phase, half of the participants received neutral instructions at test while the other half received instructions making a direct, explicit reference to the training phase. We first aimed to assess whether implicit learning operated in the two test conditions. We then evaluated the differential impact of age on learning performances as a function of test instructions. The results showed that performance did not vary as a function of age in the implicit instructions condition, while age effects emerged when explicit instructions were employed at test. However, performance was affected differently by age and the instructions given at test, depending on whether the implicit learning of short or long units was assessed. These results suggest that the claim that the implicit learning process is independent of age needs to be revised. PMID:23326409

  20. Using the Implicit Association Test to Assess Children's Implicit Attitudes toward Smoking

    PubMed Central

    Andrews, Judy A.; Hampson, Sarah E.; Greenwald, Anthony G.; Gordon, Judith; Widdop, Chris

    2009-01-01

    The development and psychometric properties of an Implicit Association Test (IAT) measuring implicit attitude toward smoking among fifth grade children were described. The IAT with “sweets” as the contrast category resulted in higher correlations with explicit attitudes than did the IAT with “healthy foods” as the contrast category. Children with family members who smoked (versus non-smoking) and children who were high in sensation seeking (versus low) had a significantly more favorable implicit attitude toward smoking. Further, implicit attitudes became less favorable after engaging in tobacco prevention activities targeting risk perceptions of addiction. Results support the reliability and validity of this version of the IAT and illustrate its usefulness in assessing young children's implicit attitude toward smoking. PMID:21566676

  1. Implicit Associations Have a Circadian Rhythm

    PubMed Central

    Zadra, Jonathan R.; Proffitt, Dennis R.

    2014-01-01

    The current study shows that people's ability to inhibit implicit associations that run counter to their explicit views varies in a circadian pattern. The presence of this rhythmic variation suggests the involvement of a biological process in regulating automatic associations—specifically, with the current data, associations that form undesirable social biases. In 1998, Greenwald, McGhee, and Schwartz introduced the Implicit Association Test as a means of measuring individual differences in implicit cognition. The IAT is a powerful tool that has become widely used. Perhaps most visibly, studies employing the IAT demonstrate that people generally hold implicit biases against social groups, which often conflict with their explicitly held views. The IAT engages inhibitory processes similar to those inherent in self-control tasks. Because the latter processes are known to be resource-limited, we considered whether IAT scores might likewise be resource dependent. Analyzing IAT performance from over a million participants across all times of day, we found a clear circadian pattern in scores. This finding suggests that the IAT measures not only the strength of implicit associations, but also the effect of variations in the physiological resources available to inhibit their undesirable influences on explicit behavior. PMID:25365254

  2. Parallel Implicit Kinetic Simulation with PARSEK

    NASA Astrophysics Data System (ADS)

    Stefano, Markidis; Giovanni, Lapenta

    2004-11-01

    Kinetic plasma simulation is the ultimate tool for plasma analysis. One of the prime tools for kinetic simulation is the particle in cell (PIC) method. The explicit or semi-implicit (i.e. implicit only on the fields) PIC method requires exceedingly small time steps and grid spacing, limited by the necessity to resolve the electron plasma frequency, the Debye length and the speed of light (for fully explicit schemes). A different approach is to consider fully implicit PIC methods where both particles and fields are discretized implicitly. This approach allows radically larger time steps and grid spacing, reducing the cost of a simulation by orders of magnitude while keeping the full kinetic treatment. In our previous work, simulations impossible for the explicit PIC method even on massively parallel computers have been made possible on a single processor machine using the implicit PIC code CELESTE3D [1]. We propose here another quantum leap: PARSEK, a parallel cousin of CELESTE3D, based on the same approach but sporting a radically redesigned software architecture (object oriented C++, where CELESTE3D was structured and written in FORTRAN77/90) and fully parallelized using MPI for both particle and grid communication. [1] G. Lapenta, J.U. Brackbill, W.S. Daughton, Phys. Plasmas, 10, 1577 (2003).

  3. Small Group Learning: Do Group Members' Implicit Theories of Ability Make a Difference?

    ERIC Educational Resources Information Center

    Beckmann, Nadin; Wood, Robert E.; Minbashian, Amirali; Tabernero, Carmen

    2012-01-01

    We examined the impact of members' implicit theories of ability on group learning and the mediating role of several group process variables, such as goal-setting, effort attributions, and efficacy beliefs. Comparisons were between 15 groups with a strong incremental view on ability (high incremental theory groups), and 15 groups with a weak…

  4. When Does Less Yield More? The Impact of Severity upon Implicit Recognition in Pure Alexia

    ERIC Educational Resources Information Center

    Roberts, Daniel J.; Lambon Ralph, Matthew A.; Woollams, Anna M.

    2010-01-01

    Pure alexia (PA) is characterised by strong effects of word length on reading times and is sometimes accompanied by an overt letter-by-letter (LBL) reading strategy. Past studies have reported "implicit recognition" in some individual PA patients. This is a striking finding because such patients are able to perform semantic classification and…

  5. Teachers' implicit "theories" of children's intelligence.

    PubMed

    Murrone, J; Gynther, M D

    1991-12-01

    Information about teachers' implicit notions of children's intelligence was obtained by having 50 student-teachers and 79 teachers with 1 to 4 years of experience rate 150 descriptors on applicability to an hypothetical child described as above average, average, or below average in intellectual functioning. Each teacher-subject was classified by dogmatism score and by years of teaching experience. A factor analysis disclosed that Academic Skills and Interpersonal Competencies summarize the implicit notions. Analysis of variance showed that all levels of hypothesized intelligence only affected teachers' expectations of academic skills and that the effect of intelligence was dependent upon the teachers' dogmatism. There were no clear-cut findings associated with years of experience. Results supported previous observations that people have implicit "theories" of intelligence; however, the specific composition of their ideas varies according to the context within which the rater and the person observed are placed. PMID:1792291

  6. State-Based Implicit Coordination and Applications

    NASA Technical Reports Server (NTRS)

    Narkawicz, Anthony J.; Munoz, Cesar A.

    2011-01-01

    In air traffic management, pairwise coordination is the ability to achieve separation requirements when conflicting aircraft simultaneously maneuver to solve a conflict. Resolution algorithms are implicitly coordinated if they provide coordinated resolution maneuvers to conflicting aircraft when only surveillance data, e.g., position and velocity vectors, is periodically broadcast by the aircraft. This paper proposes an abstract framework for reasoning about state-based implicit coordination. The framework consists of a formalized mathematical development that enables and simplifies the design and verification of implicitly coordinated state-based resolution algorithms. The use of the framework is illustrated with several examples of algorithms and formal proofs of their coordination properties. The work presented here supports the safety case for a distributed self-separation air traffic management concept where different aircraft may use different conflict resolution algorithms and be assured that separation will be maintained.

  7. Précis of implicit nationalism.

    PubMed

    Hassin, Ran R; Ferguson, Melissa J; Kardosh, Rasha; Porter, Shanette C; Carter, Travis J; Dudareva, Veronika

    2009-06-01

    While the study of nationalism has received much attention throughout the social sciences and humanities, the experimental investigation of it lags behind. In this paper we review recent advances in the examination of implicit nationalism. In the first set of experiments we survey, the Palestinian, Israeli, Italian, and Russian flags were primed (or not, in the control conditions) and their effects on political thought and behavior were tested. In the second set the American or the Israeli flag was primed (or not) and prejudice toward African-Americans or Palestinians (respectively) was examined. The results of all experiments suggest that the implicit activation of national cues has far-reaching implications on political thought and behavior as well as on attitudes toward minorities. Under the assumption that the image of national flags is associated in memory with national ideologies, these results suggest that national ideologies can be implicitly pursued in a way that significantly affects our thoughts and behaviors. PMID:19580560

  8. Testosterone abolishes implicit subordination in social anxiety.

    PubMed

    Terburg, David; Syal, Supriya; Rosenberger, Lisa A; Heany, Sarah J; Stein, Dan J; Honk, Jack van

    2016-10-01

    Neuro-evolutionary theories describe social anxiety as habitual subordinate tendencies acquired through a recursive cycle of social defeat and submissive reactions. If so, the steroid hormone testosterone might be of therapeutic value, as testosterone is a main force behind implicit dominance drive in many species including humans. We combined these two theories to investigate whether the tendency to submit to the dominance of others is an implicit mechanism in social anxiety (Study-1), and whether this can be relieved through testosterone administration (Study-2). Using interactive eye-tracking we demonstrate that socially anxious humans more rapidly avert gaze from subliminal angry eye contact (Study-1). We replicate this effect of implicit subordination in social anxiety in an independent sample, which is subsequently completely abolished after a single placebo-controlled sublingual testosterone administration (Study-2). These findings provide crucial evidence for hormonal and behavioral treatment strategies that specifically target mechanisms of dominance and subordination in social anxiety. PMID:27448713

  9. Implicit verbal memory in Alzheimer's disease.

    PubMed

    Russo, R; Spinnler, H

    1994-09-01

    Word stem completion and word identification were used in two repetition priming experiments to evaluate the implicit memory performance of Alzheimer's disease (AD) patients. This issue was also approached using various meta-analyses combining and contrasting previously reported data. While the experimental results suggested that AD patients present preserved repetition priming in both tasks, the meta-analytic approach showed an impairment in stem completion in comparison to word identification. Converging evidence cautiously suggested to accept the results of the meta-analysis. The above dissociation has been interpreted as showing differences in the specific contribution of data- and conceptually-driven processes in the two implicit tasks. A further meta-analysis on the effect of reduced perceptual availability of the study material on the same two tasks indicated that this variable affected repetition priming in word identification more heavily than in stem completion. The impact of such a dissociation on theories of implicit memory is discussed. PMID:7805380

  10. Implicit solvent methods for free energy estimation

    PubMed Central

    Decherchi, Sergio; Masetti, Matteo; Vyalov, Ivan; Rocchia, Walter

    2014-01-01

    Solvation is a fundamental contribution in many biological processes and especially in molecular binding. Its estimation can be performed by means of several computational approaches. The aim of this review is to give an overview of existing theories and methods to estimate solvent effects giving a specific focus on the category of implicit solvent models and their use in Molecular Dynamics. In many of these models, the solvent is considered as a continuum homogenous medium, while the solute can be represented at the atomic detail and at different levels of theory. Despite their degree of approximation, implicit methods are still widely employed due to their trade-off between accuracy and efficiency. Their derivation is rooted in the statistical mechanics and integral equations disciplines, some of the related details being provided here. Finally, methods that combine implicit solvent models and molecular dynamics simulation, are briefly described. PMID:25193298

  11. Implicit Memory in Music and Language

    PubMed Central

    Ettlinger, Marc; Margulis, Elizabeth H.; Wong, Patrick C. M.

    2011-01-01

    Research on music and language in recent decades has focused on their overlapping neurophysiological, perceptual, and cognitive underpinnings, ranging from the mechanism for encoding basic auditory cues to the mechanism for detecting violations in phrase structure. These overlaps have most often been identified in musicians with musical knowledge that was acquired explicitly, through formal training. In this paper, we review independent bodies of work in music and language that suggest an important role for implicitly acquired knowledge, implicit memory, and their associated neural structures in the acquisition of linguistic or musical grammar. These findings motivate potential new work that examines music and language comparatively in the context of the implicit memory system. PMID:21927608

  12. Dissociations between familiarity processes in explicit recognition and implicit perceptual memory.

    PubMed

    Wagner, A D; Gabrieli, J D; Verfaellie, M

    1997-03-01

    Dual-process theories of recognition posit that a perceptual familiarity process contributes to both explicit recognition and implicit perceptual memory. This putative single familiarity process has been indexed by inclusion-exclusion, remember-know, and repetition priming measures. The present studies examined whether these measures identify a common familiarity process. Familiarity-based explicit recognition (as indexed by the inclusion-exclusion and the independence remember-know procedures) increased with conceptual processing. In contrast, implicit word-identification priming and familiarity-based word-stem completion (as indexed by inclusion-exclusion) increased with study-test perceptual similarity. These dissociations indicate that familiarity-based explicit recognition may be more sensitive to conceptual than to perceptual processing and is functionally distinct from the perceptual familiarity process mediating implicit perceptual memory. PMID:9080006

  13. Large spatial, temporal, and algorithmic adaptivity for implicit nonlinear finite element analysis

    SciTech Connect

    Engelmann, B.E.; Whirley, R.G.

    1992-07-30

    The development of effective solution strategies to solve the global nonlinear equations which arise in implicit finite element analysis has been the subject of much research in recent years. Robust algorithms are needed to handle the complex nonlinearities that arise in many implicit finite element applications such as metalforming process simulation. The authors experience indicates that robustness can best be achieved through adaptive solution strategies. In the course of their research, this adaptivity and flexibility has been refined into a production tool through the development of a solution control language called ISLAND. This paper discusses aspects of adaptive solution strategies including iterative procedures to solve the global equations and remeshing techniques to extend the domain of Lagrangian methods. Examples using the newly developed ISLAND language are presented to illustrate the advantages of embedding temporal, algorithmic, and spatial adaptivity in a modem implicit nonlinear finite element analysis code.

  14. Processing implicit control: evidence from reading times

    PubMed Central

    McCourt, Michael; Green, Jeffrey J.; Lau, Ellen; Williams, Alexander

    2015-01-01

    Sentences such as “The ship was sunk to collect the insurance” exhibit an unusual form of anaphora, implicit control, where neither anaphor nor antecedent is audible. The non-finite reason clause has an understood subject, PRO, that is anaphoric; here it may be understood as naming the agent of the event of the host clause. Yet since the host is a short passive, this agent is realized by no audible dependent. The putative antecedent to PRO is therefore implicit, which it normally cannot be. What sorts of representations subserve the comprehension of this dependency? Here we present four self-paced reading time studies directed at this question. Previous work showed no processing cost for implicit vs. explicit control, and took this to support the view that PRO is linked syntactically to a silent argument in the passive. We challenge this conclusion by reporting that we also find no processing cost for remote implicit control, as in: “The ship was sunk. The reason was to collect the insurance.” Here the dependency crosses two independent sentences, and so cannot, we argue, be mediated by syntax. Our Experiments 1–4 examined the processing of both implicit (short passive) and explicit (active or long passive) control in both local and remote configurations. Experiments 3 and 4 added either “3 days ago” or “just in order” to the local conditions, to control for the distance between the passive and infinitival verbs, and for the predictability of the reason clause, respectively. We replicate the finding that implicit control does not impose an additional processing cost. But critically we show that remote control does not impose a processing cost either. Reading times at the reason clause were never slower when control was remote. In fact they were always faster. Thus, efficient processing of local implicit control cannot show that implicit control is mediated by syntax; nor, in turn, that there is a silent but grammatically active argument in

  15. Implicit structured sequence learning: an fMRI study of the structural mere-exposure effect.

    PubMed

    Folia, Vasiliki; Petersson, Karl Magnus

    2014-01-01

    In this event-related fMRI study we investigated the effect of 5 days of implicit acquisition on preference classification by means of an artificial grammar learning (AGL) paradigm based on the structural mere-exposure effect and preference classification using a simple right-linear unification grammar. This allowed us to investigate implicit AGL in a proper learning design by including baseline measurements prior to grammar exposure. After 5 days of implicit acquisition, the fMRI results showed activations in a network of brain regions including the inferior frontal (centered on BA 44/45) and the medial prefrontal regions (centered on BA 8/32). Importantly, and central to this study, the inclusion of a naive preference fMRI baseline measurement allowed us to conclude that these fMRI findings were the intrinsic outcomes of the learning process itself and not a reflection of a preexisting functionality recruited during classification, independent of acquisition. Support for the implicit nature of the knowledge utilized during preference classification on day 5 come from the fact that the basal ganglia, associated with implicit procedural learning, were activated during classification, while the medial temporal lobe system, associated with explicit declarative memory, was consistently deactivated. Thus, preference classification in combination with structural mere-exposure can be used to investigate structural sequence processing (syntax) in unsupervised AGL paradigms with proper learning designs. PMID:24550865

  16. The Intergenerational Transmission of Implicit and Explicit Attitudes Toward Smoking

    PubMed Central

    Sherman, Steven J.; Chassin, Laurie; Presson, Clark; Seo, Dong-Chul; Macy, Jonathan T.

    2009-01-01

    This study examined the intergenerational transmission of implicit and explicit attitudes toward smoking, as well as the role of these attitudes in adolescents’ smoking initiation. There was evidence of intergenerational transmission of implicit attitudes. Mothers who had more positive implicit attitudes had children with more positive implicit attitudes. In turn, these positive implicit attitudes of adolescents predicted their smoking initiation 18-months later. Moreover, these effects were obtained above and beyond the effects of explicit attitudes. These findings provide the first evidence that the intergenerational transmission of implicit cognition may play a role in the intergenerational transmission of an addictive behavior. PMID:20126293

  17. Implicit and explicit anti-fat bias among a large sample of medical doctors by BMI, race/ethnicity and gender.

    PubMed

    Sabin, Janice A; Marini, Maddalena; Nosek, Brian A

    2012-01-01

    Overweight patients report weight discrimination in health care settings and subsequent avoidance of routine preventive health care. The purpose of this study was to examine implicit and explicit attitudes about weight among a large group of medical doctors (MDs) to determine the pervasiveness of negative attitudes about weight among MDs. Test-takers voluntarily accessed a public Web site, known as Project Implicit®, and opted to complete the Weight Implicit Association Test (IAT) (N = 359,261). A sub-sample identified their highest level of education as MD (N = 2,284). Among the MDs, 55% were female, 78% reported their race as white, and 62% had a normal range BMI. This large sample of test-takers showed strong implicit anti-fat bias (Cohen's d = 1.0). MDs, on average, also showed strong implicit anti-fat bias (Cohen's d = 0.93). All test-takers and the MD sub-sample reported a strong preference for thin people rather than fat people or a strong explicit anti-fat bias. We conclude that strong implicit and explicit anti-fat bias is as pervasive among MDs as it is among the general public. An important area for future research is to investigate the association between providers' implicit and explicit attitudes about weight, patient reports of weight discrimination in health care, and quality of care delivered to overweight patients. PMID:23144885

  18. Implicit and Explicit Anti-Fat Bias among a Large Sample of Medical Doctors by BMI, Race/Ethnicity and Gender

    PubMed Central

    Sabin, Janice A.; Marini, Maddalena; Nosek, Brian A.

    2012-01-01

    Overweight patients report weight discrimination in health care settings and subsequent avoidance of routine preventive health care. The purpose of this study was to examine implicit and explicit attitudes about weight among a large group of medical doctors (MDs) to determine the pervasiveness of negative attitudes about weight among MDs. Test-takers voluntarily accessed a public Web site, known as Project Implicit®, and opted to complete the Weight Implicit Association Test (IAT) (N = 359,261). A sub-sample identified their highest level of education as MD (N = 2,284). Among the MDs, 55% were female, 78% reported their race as white, and 62% had a normal range BMI. This large sample of test-takers showed strong implicit anti-fat bias (Cohen’s d = 1.0). MDs, on average, also showed strong implicit anti-fat bias (Cohen’s d = 0.93). All test-takers and the MD sub-sample reported a strong preference for thin people rather than fat people or a strong explicit anti-fat bias. We conclude that strong implicit and explicit anti-fat bias is as pervasive among MDs as it is among the general public. An important area for future research is to investigate the association between providers’ implicit and explicit attitudes about weight, patient reports of weight discrimination in health care, and quality of care delivered to overweight patients. PMID:23144885

  19. Adapting implicit methods to parallel processors

    SciTech Connect

    Reeves, L.; McMillin, B.; Okunbor, D.; Riggins, D.

    1994-12-31

    When numerically solving many types of partial differential equations, it is advantageous to use implicit methods because of their better stability and more flexible parameter choice, (e.g. larger time steps). However, since implicit methods usually require simultaneous knowledge of the entire computational domain, these methods axe difficult to implement directly on distributed memory parallel processors. This leads to infrequent use of implicit methods on parallel/distributed systems. The usual implementation of implicit methods is inefficient due to the nature of parallel systems where it is common to take the computational domain and distribute the grid points over the processors so as to maintain a relatively even workload per processor. This creates a problem at the locations in the domain where adjacent points are not on the same processor. In order for the values at these points to be calculated, messages have to be exchanged between the corresponding processors. Without special adaptation, this will result in idle processors during part of the computation, and as the number of idle processors increases, the lower the effective speed improvement by using a parallel processor.

  20. Implicit Memory, Age, and Time of Day

    PubMed Central

    May, Cynthia P.; Hasher, Lynn; Foong, Natalie

    2006-01-01

    Memory retrieval can occur by at least two routes: a deliberate one, as when one attempts to retrieve an event or fact, and an unintentional one, as when one’s behavior is triggered by the past without one’s knowledge or awareness. We assessed the efficacy of these retrieval systems as a function of circadian arousal and time of day. Evening-type younger adults and morning-type older adults were tested at either peak (morning for old; evening for young) or off-peak times on implicit and explicit stem completion (Experiment 1) or on implicit category generation (Experiment 2). Results for explicit stem-cued recall replicated better performance for each age group at its peak time. In stark contrast, implicit performance was better at off-peak than at peak times of day, raising the possibility that the processes that serve explicit and implicit retrieval are on different circadian schedules, and highlighting the need to consider individual differences in circadian arousal when assessing either memory system. PMID:15686574

  1. Strategic Game Moves Mediate Implicit Science Learning

    ERIC Educational Resources Information Center

    Rowe, Elizabeth; Baker, Ryan S.; Asbell-Clarke, Jodi

    2015-01-01

    Educational games have the potential to be innovative forms of learning assessment, by allowing us to not just study their knowledge but the process that takes students to that knowledge. This paper examines the mediating role of players' moves in digital games on changes in their pre-post classroom measures of implicit science learning. We…

  2. Implicit Reading in Chinese Pure Alexia

    ERIC Educational Resources Information Center

    Shan, Chunlei; Zhu, Renjing; Xu, Mingwei; Luo, Benyan; Weng, Xuchu

    2010-01-01

    A number of recent studies have shown that some patients with pure alexia display evidence of implicit access to lexical and semantic information about words that they cannot read explicitly. This phenomenon has not been investigated systematically in Chinese patients. We report here a case study of a Chinese patient who met the criteria for pure…

  3. Implicit Learning of Semantic Preferences of Verbs

    ERIC Educational Resources Information Center

    Paciorek, Albertyna; Williams, John N.

    2015-01-01

    Previous studies of semantic implicit learning in language have only examined learning grammatical form-meaning connections in which learning could have been supported by prior linguistic knowledge. In this study we target the domain of verb meaning, specifically semantic preferences regarding novel verbs (e.g., the preference for a novel verb to…

  4. Implicit Assumptions in High Potentials Recruitment

    ERIC Educational Resources Information Center

    Posthumus, Jan; Bozer, Gil; Santora, Joseph C.

    2016-01-01

    Purpose: Professionals of human resources (HR) use different criteria in practice than they verbalize. Thus, the aim of this research was to identify the implicit criteria used for the selection of high-potential employees in recruitment and development settings in the pharmaceutical industry. Design/methodology/approach: A semi-structured…

  5. An Implicit Test of Chinese Orthographic Satiation

    ERIC Educational Resources Information Center

    Cheng, Chao-Ming; Lan, Ying-Hsiang

    2011-01-01

    In this research, an implicit test using a lexical-decision task, in which words were discriminated from homophonic pseudo-words, was developed to detect the phenomenon of "Chinese orthographic satiation." The phenomenon is defined as a sense of uncertainty of the composition of a well-learned Chinese character through a prolonged visual…

  6. Crosslinguistic Differences in Implicit Language Learning

    ERIC Educational Resources Information Center

    Leung, Janny H. C.; Williams, John N.

    2014-01-01

    We report three experiments that explore the effect of prior linguistic knowledge on implicit language learning. Native speakers of English from the United Kingdom and native speakers of Cantonese from Hong Kong participated in experiments that involved different learning materials. In Experiment 1, both participant groups showed evidence of…

  7. Implicit theories and ability emotional intelligence.

    PubMed

    Cabello, Rosario; Fernández-Berrocal, Pablo

    2015-01-01

    Previous research has shown that people differ in their implicit theories about the essential characteristics of intelligence and emotions. Some people believe these characteristics to be predetermined and immutable (entity theorists), whereas others believe that these characteristics can be changed through learning and behavior training (incremental theorists). The present study provides evidence that in healthy adults (N = 688), implicit beliefs about emotions and emotional intelligence (EI) may influence performance on the ability-based Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). Adults in our sample with incremental theories about emotions and EI scored higher on the MSCEIT than entity theorists, with implicit theories about EI showing a stronger relationship to scores than theories about emotions. Although our participants perceived both emotion and EI as malleable, they viewed emotions as more malleable than EI. Women and young adults in general were more likely to be incremental theorists than men and older adults. Furthermore, we found that emotion and EI theories mediated the relationship of gender and age with ability EI. Our findings suggest that people's implicit theories about EI may influence their emotional abilities, which may have important consequences for personal and professional EI training. PMID:26052309

  8. Thinking Styles in Implicit and Explicit Learning

    ERIC Educational Resources Information Center

    Xie, Qiuzhi; Gao, Xiangping; King, Ronnel B.

    2013-01-01

    This study investigated whether individual differences in thinking styles influence explicit and implicit learning. Eighty-seven university students in China participated in this study. Results indicated that performance in the explicit learning condition was positively associated with Type I thinking styles (i.e. legislative and liberal styles)…

  9. Affective Objectives--Implicit or Explicit?

    ERIC Educational Resources Information Center

    Smith, Hayden R.; Enos, Donald F.

    The author discusses the importance of affective objectives in the educational process, and the difficulties in formulating, providing activities in, and evaluating the attainment of these objectives. A distinction is drawn between explicit objectives (those that should be revealed to the student) and implicit objectives (those that are…

  10. Age effects on explicit and implicit memory

    PubMed Central

    Ward, Emma V.; Berry, Christopher J.; Shanks, David R.

    2013-01-01

    It is well-documented that explicit memory (e.g., recognition) declines with age. In contrast, many argue that implicit memory (e.g., priming) is preserved in healthy aging. For example, priming on tasks such as perceptual identification is often not statistically different in groups of young and older adults. Such observations are commonly taken as evidence for distinct explicit and implicit learning/memory systems. In this article we discuss several lines of evidence that challenge this view. We describe how patterns of differential age-related decline may arise from differences in the ways in which the two forms of memory are commonly measured, and review recent research suggesting that under improved measurement methods, implicit memory is not age-invariant. Formal computational models are of considerable utility in revealing the nature of underlying systems. We report the results of applying single and multiple-systems models to data on age effects in implicit and explicit memory. Model comparison clearly favors the single-system view. Implications for the memory systems debate are discussed. PMID:24065942

  11. Can Musical Transformations Be Implicitly Learned?

    ERIC Educational Resources Information Center

    Dienes, Zoltan; Longuet-Higgins, Christopher

    2004-01-01

    The dominant theory of what people can learn implicitly is that they learn chunks of adjacent elements in sequences. A type of musical grammar that goes beyond specifying allowable chunks is provided by serialist or 12-tone music. The rules constitute operations over variables and could not be appreciated as such by a system that can only chunk…

  12. Implicit Measures of Association in Psychopathology Research

    ERIC Educational Resources Information Center

    Roefs, Anne; Huijding, Jorg; Smulders, Fren T. Y.; MacLeod, Colin M.; de Jong, Peter J.; Wiers, Reinout W.; Jansen, Anita T. M.

    2011-01-01

    Validity;Measures (Individuals);Studies obtaining implicit measures of associations in "Diagnostic and Statistical Manual of Mental Disorders" (4th ed., Text Revision; American Psychiatric Association, 2000) Axis I psychopathology are organized into three categories: (a) studies comparing groups having a disorder with controls, (b) experimental…

  13. Measuring Gifted Adolescents' Implicit Theories of Creativity

    ERIC Educational Resources Information Center

    Wickes, Katherine N. Saunders; Ward, Thomas B.

    2006-01-01

    This paper examines the structure of implicit theories of creativity in a sample of gifted adolescents and describes the development and use of the Creative Self Checklist and the Creative Individual Checklist, adjective checklists designed to assess endorsement of creativity-related personality and behavioral attributes. Findings indicate that…

  14. Semantic generalization in implicit language learning.

    PubMed

    Paciorek, Albertyna; Williams, John N

    2015-07-01

    Despite many years of investigation into implicit learning in nonlinguistic domains, the potential for implicit learning to deliver the kinds of generalizations that underlie natural language competence remains unclear. In a series of experiments, we investigated implicit learning of the semantic preferences of novel verbs, specifically, whether they collocate with abstract or concrete nouns. After reading sentences containing the verbs, participants were required to judge the familiarity of pairs of novel verbs and nouns and to indicate their confidence or the basis of their judgment (i.e., guess, intuition, memory). Although all of the words had occurred in the texts, none of the critical items had actually occurred together. However, endorsement rates were significantly higher for pairs that respected the semantic preference rules than those that did not. Through analysis of subjective measures and verbal report, we argue that, for the majority of participants, this effect was based on unconscious knowledge. We argue that implicit learning of the kind of generalizations underlying semantic preferences is possible even after limited exposure. PMID:25581225

  15. Implicit emotion regulation affects outcome evaluation.

    PubMed

    Yang, Qiwei; Tang, Ping; Gu, Ruolei; Luo, Wenbo; Luo, Yue-jia

    2015-06-01

    Efficient implicit emotion regulation processes, which run without awareness, are important for human well-being. In this study, to investigate the influence of implicit emotion regulation on psychological and electrophysiological responses to gains and losses, participants were required to select between two Chinese four-character idioms to match the meaning of the third one before they performed a monetary gambling task. According to whether their meanings were related to emotion regulation, the idioms fell into two categories. Event-related potentials and self-rating emotional experiences to outcome feedback were recorded during the task. Priming emotion regulation reduced subjective emotional experience to both gains and losses and the amplitudes of the feedback-related negativity, while the P3 component was not influenced. According to these results, we suggest that the application of implicit emotion regulation effectively modulated the subjective emotional experience and the motivational salience of current outcomes without the cost of cognitive resources. This study implicates the potential significance of implicit emotion regulation in decision-making processes. PMID:25332404

  16. Identifying, Quantifying, Extracting and Enhancing Implicit Parallelism

    ERIC Educational Resources Information Center

    Agarwal, Mayank

    2009-01-01

    The shift of the microprocessor industry towards multicore architectures has placed a huge burden on the programmers by requiring explicit parallelization for performance. Implicit Parallelization is an alternative that could ease the burden on programmers by parallelizing applications "under the covers" while maintaining sequential semantics…

  17. The single category implicit association test as a measure of implicit social cognition.

    PubMed

    Karpinski, Andrew; Steinman, Ross B

    2006-07-01

    The Single Category Implicit Association Test (SC-IAT) is a modification of the Implicit Association Test that measures the strength of evaluative associations with a single attitude object. Across 3 different attitude domains--soda brand preferences, self-esteem, and racial attitudes--the authors found evidence that the SC-IAT is internally consistent and makes unique contributions in the ability to understand implicit social cognition. In a 4th study, the authors investigated the susceptibility of the SC-IAT to faking or self-presentational concerns. Once participants with high error rates were removed, no significant self-presentation effect was observed. These results provide initial evidence for the reliability and validity of the SC-IAT as an individual difference measure of implicit social cognition. PMID:16834477

  18. Multigrid Methods for Fully Implicit Oil Reservoir Simulation

    NASA Technical Reports Server (NTRS)

    Molenaar, J.

    1996-01-01

    In this paper we consider the simultaneous flow of oil and water in reservoir rock. This displacement process is modeled by two basic equations: the material balance or continuity equations and the equation of motion (Darcy's law). For the numerical solution of this system of nonlinear partial differential equations there are two approaches: the fully implicit or simultaneous solution method and the sequential solution method. In the sequential solution method the system of partial differential equations is manipulated to give an elliptic pressure equation and a hyperbolic (or parabolic) saturation equation. In the IMPES approach the pressure equation is first solved, using values for the saturation from the previous time level. Next the saturations are updated by some explicit time stepping method; this implies that the method is only conditionally stable. For the numerical solution of the linear, elliptic pressure equation multigrid methods have become an accepted technique. On the other hand, the fully implicit method is unconditionally stable, but it has the disadvantage that in every time step a large system of nonlinear algebraic equations has to be solved. The most time-consuming part of any fully implicit reservoir simulator is the solution of this large system of equations. Usually this is done by Newton's method. The resulting systems of linear equations are then either solved by a direct method or by some conjugate gradient type method. In this paper we consider the possibility of applying multigrid methods for the iterative solution of the systems of nonlinear equations. There are two ways of using multigrid for this job: either we use a nonlinear multigrid method or we use a linear multigrid method to deal with the linear systems that arise in Newton's method. So far only a few authors have reported on the use of multigrid methods for fully implicit simulations. Two-level FAS algorithm is presented for the black-oil equations, and linear multigrid for

  19. Neural networks underlying implicit and explicit moral evaluations in psychopathy

    PubMed Central

    Yoder, K J; Harenski, C; Kiehl, K A; Decety, J

    2015-01-01

    Psychopathy, characterized by symptoms of emotional detachment, reduced guilt and empathy and a callous disregard for the rights and welfare of others, is a strong risk factor for immoral behavior. Psychopathy is also marked by abnormal attention with downstream consequences on emotional processing. To examine the influence of task demands on moral evaluation in psychopathy, functional magnetic resonance imaging was used to measure neural response and functional connectivity in 88 incarcerated male subjects (28 with Psychopathy Checklist Revised (PCL-R) scores ⩾30) while they viewed dynamic visual stimuli depicting interpersonal harm and interpersonal assistance in two contexts, implicit and explicit. During the implicit task, high psychopathy was associated with reduced activity in the dorsolateral prefrontal cortex and caudate when viewing harmful compared with helpful social interactions. Functional connectivity seeded in the right amygdala and right temporoparietal junction revealed decreased coupling with the anterior cingulate cortex (ACC), anterior insula, striatum and ventromedial prefrontal cortex. In the explicit task, higher trait psychopathy predicted reduced signal change in ACC and amygdala, accompanied by decreased functional connectivity to temporal pole, insula and striatum, but increased connectivity with dorsal ACC. Psychopathy did not influence behavioral performance in either task, despite differences in neural activity and functional connectivity. These findings provide the first direct evidence that hemodynamic activity and neural coupling within the salience network are disrupted in psychopathy, and that the effects of psychopathy on moral evaluation are influenced by attentional demands. PMID:26305476

  20. Neural networks underlying implicit and explicit moral evaluations in psychopathy.

    PubMed

    Yoder, K J; Harenski, C; Kiehl, K A; Decety, J

    2015-01-01

    Psychopathy, characterized by symptoms of emotional detachment, reduced guilt and empathy and a callous disregard for the rights and welfare of others, is a strong risk factor for immoral behavior. Psychopathy is also marked by abnormal attention with downstream consequences on emotional processing. To examine the influence of task demands on moral evaluation in psychopathy, functional magnetic resonance imaging was used to measure neural response and functional connectivity in 88 incarcerated male subjects (28 with Psychopathy Checklist Revised (PCL-R) scores ⩾ 30) while they viewed dynamic visual stimuli depicting interpersonal harm and interpersonal assistance in two contexts, implicit and explicit. During the implicit task, high psychopathy was associated with reduced activity in the dorsolateral prefrontal cortex and caudate when viewing harmful compared with helpful social interactions. Functional connectivity seeded in the right amygdala and right temporoparietal junction revealed decreased coupling with the anterior cingulate cortex (ACC), anterior insula, striatum and ventromedial prefrontal cortex. In the explicit task, higher trait psychopathy predicted reduced signal change in ACC and amygdala, accompanied by decreased functional connectivity to temporal pole, insula and striatum, but increased connectivity with dorsal ACC. Psychopathy did not influence behavioral performance in either task, despite differences in neural activity and functional connectivity. These findings provide the first direct evidence that hemodynamic activity and neural coupling within the salience network are disrupted in psychopathy, and that the effects of psychopathy on moral evaluation are influenced by attentional demands. PMID:26305476

  1. Implicit emotional processing in peripheral vision: behavioral and neural evidence.

    PubMed

    Rigoulot, Simon; D'Hondt, Fabien; Honoré, Jacques; Sequeira, Henrique

    2012-10-01

    Emotional facial expressions (EFE) are efficiently processed when both attention and gaze are focused on them. However, what kind of processing persists when EFE are neither the target of attention nor of gaze remains largely unknown. Consequently, in this experiment we investigated whether the implicit processing of faces displayed in far periphery could still be modulated by their emotional expression. Happy, fearful and neutral faces appeared randomly for 300 ms at four peripheral locations of a panoramic screen (15 and 30° in the right and left visual fields). Reaction times and electrophysiological responses were recorded from 32 participants who had to categorize these faces according to their gender. A decrease of behavioral performance was specifically found for happy and fearful faces, probably because emotional content was automatically processed and interfered with information necessary to the task. A spatio-temporal principal component analysis of electrophysiological data confirmed an enhancement of early activity in occipito-temporal areas for emotional faces in comparison with neutral ones. Overall, these data show an implicit processing of EFE despite the strong decrease of visual performance with eccentricity. Therefore, the present research suggests that EFE could be automatically detected in peripheral vision, confirming the abilities of humans to process emotional saliency in very impoverished conditions of vision. PMID:22944003

  2. Implicit Priors in Galaxy Cluster Mass and Scaling Relation Determinations

    NASA Technical Reports Server (NTRS)

    Mantz, A.; Allen, S. W.

    2011-01-01

    Deriving the total masses of galaxy clusters from observations of the intracluster medium (ICM) generally requires some prior information, in addition to the assumptions of hydrostatic equilibrium and spherical symmetry. Often, this information takes the form of particular parametrized functions used to describe the cluster gas density and temperature profiles. In this paper, we investigate the implicit priors on hydrostatic masses that result from this fully parametric approach, and the implications of such priors for scaling relations formed from those masses. We show that the application of such fully parametric models of the ICM naturally imposes a prior on the slopes of the derived scaling relations, favoring the self-similar model, and argue that this prior may be influential in practice. In contrast, this bias does not exist for techniques which adopt an explicit prior on the form of the mass profile but describe the ICM non-parametrically. Constraints on the slope of the cluster mass-temperature relation in the literature show a separation based the approach employed, with the results from fully parametric ICM modeling clustering nearer the self-similar value. Given that a primary goal of scaling relation analyses is to test the self-similar model, the application of methods subject to strong, implicit priors should be avoided. Alternative methods and best practices are discussed.

  3. Implicit Misattribution as a Mechanism Underlying Evaluative Conditioning

    PubMed Central

    Jones, Christopher R.; Fazio, Russell H.; Olson, Michael A.

    2009-01-01

    Evaluative conditioning (EC) refers to the formation or change of an attitude towards an object following that object’s pairing with positively or negatively valenced stimuli. We provide evidence that EC can occur through an implicit misattribution mechanism in which an evaluative response evoked by a valenced stimulus is incorrectly and implicitly attributed to another stimulus, forming or changing an attitude towards this other stimulus. Five studies measured or manipulated variables related to the potential for the misattribution of an evaluation, or “source confusability.” Greater EC was observed when participants’ eye gaze shifted frequently between a valenced and neutral stimulus (Studies 1 & 2), when the two stimuli appeared in close spatial proximity (Study 3), and when the neutral stimulus was made more perceptually salient than the valenced stimulus due to its larger size (Study 4). In other words, conditions conducive to source confusability increased EC. Study 5 provided evidence for multiple mechanisms of EC by comparing the effects of mildly evocative valenced stimuli (those evoking responses that might more easily be misattributed to another object) to more strongly evocative stimuli. PMID:19379028

  4. Implicit associations in cybersex addiction: Adaption of an Implicit Association Test with pornographic pictures.

    PubMed

    Snagowski, Jan; Wegmann, Elisa; Pekal, Jaro; Laier, Christian; Brand, Matthias

    2015-10-01

    Recent studies show similarities between cybersex addiction and substance dependencies and argue to classify cybersex addiction as a behavioral addiction. In substance dependency, implicit associations are known to play a crucial role, and such implicit associations have not been studied in cybersex addiction, so far. In this experimental study, 128 heterosexual male participants completed an Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) modified with pornographic pictures. Further, problematic sexual behavior, sensitivity towards sexual excitation, tendencies towards cybersex addiction, and subjective craving due to watching pornographic pictures were assessed. Results show positive relationships between implicit associations of pornographic pictures with positive emotions and tendencies towards cybersex addiction, problematic sexual behavior, sensitivity towards sexual excitation as well as subjective craving. Moreover, a moderated regression analysis revealed that individuals who reported high subjective craving and showed positive implicit associations of pornographic pictures with positive emotions, particularly tended towards cybersex addiction. The findings suggest a potential role of positive implicit associations with pornographic pictures in the development and maintenance of cybersex addiction. Moreover, the results of the current study are comparable to findings from substance dependency research and emphasize analogies between cybersex addiction and substance dependencies or other behavioral addictions. PMID:26026385

  5. Implicit Statistical Learning and Language Skills in Bilingual Children

    ERIC Educational Resources Information Center

    Yim, Dongsun; Rudoy, John

    2013-01-01

    Purpose: Implicit statistical learning in 2 nonlinguistic domains (visual and auditory) was used to investigate (a) whether linguistic experience influences the underlying learning mechanism and (b) whether there are modality constraints in predicting implicit statistical learning with age and language skills. Method: Implicit statistical learning…

  6. Questioning Children: Interactional Evidence of Implicit Bias in Medical Interviews

    ERIC Educational Resources Information Center

    Stivers, Tanya; Majid, Asifa

    2007-01-01

    Social psychologists have shown experimentally that implicit race bias can influence an individual's behavior. Implicit bias has been suggested to be more subtle and less subject to cognitive control than more explicit forms of racial prejudice. Little is known about how implicit bias is manifest in naturally occurring social interaction. This…

  7. Implicit Referential Meaning with Reference to English Arabic Translation

    ERIC Educational Resources Information Center

    Al-Zughoul, Basem

    2014-01-01

    The purpose of this study is to investigate how English implicit referential meaning is translated into Arabic by analyzing sentences containing implicit referential meanings found in the novel "Harry Potter and the Prisoner of Azkaban". The analysis shows that the translation of English implicit referential meaning into Arabic can be…

  8. Chinese Undergraduates' Explicit and Implicit Attitudes toward Persons with Disabilities

    ERIC Educational Resources Information Center

    Chen, Shuang; Ma, Li; Zhang, Jian-Xin

    2011-01-01

    The present study is aimed at examining implicit and explicit attitudes toward persons with disabilities among Chinese college students. The "Implicit Association Test" was used to measure their implicit attitudes, whereas their explicit attitudes toward persons with disabilities were measured by using a scale of three items. Participants were 56…

  9. Gender Differences in Implicit and Explicit Memory for Affective Passages

    ERIC Educational Resources Information Center

    Burton, Leslie A.; Rabin, Laura; Vardy, Susan Bernstein.; Frohlich, Jonathan; Wyatt, Gwinne; Dimitri, Diana; Constante, Shimon; Guterman, Elan

    2004-01-01

    Thirty-two participants were administered 4 verbal tasks, an Implicit Affective Task, an Implicit Neutral Task, an Explicit Affective Task, and an Explicit Neutral Task. For the Implicit Tasks, participants were timed while reading passages aloud as quickly as possible, but not so quickly that they did not understand. A target verbal passage was…

  10. Constraints on Implicit Learning of Grammatical Form-Meaning Connections

    ERIC Educational Resources Information Center

    Leung, Janny H. C.; Williams, John N.

    2012-01-01

    Although there is good evidence for implicit learning of associations between forms, little work has investigated implicit learning of form-meaning connections, and the findings are somewhat contradictory. Two experiments were carried out using a novel reaction time methodology to investigate implicit learning of grammatical form-meaning…

  11. Believing Is Seeing: Fixation Duration Predicts Implicit Negative Attitudes

    PubMed Central

    2014-01-01

    A prototypical finding of social cognition is that social experiences influence later performance even though those experiences are not introspectively available. Building on social cognition research on implicit attitudes, we evaluate whether ethnic category/attribute pairs influence eye movements during the Implicit Association Test (IAT, Greenwald, McGhee, & Schwartz 1998). Results show that fixation duration predicted implicit attitudes such that when the category/attribute pairs disconfirmed one's implicit negative attitude fixation duration toward that pair increased. The present research provides evidence that eye movements and implicit processes inherent in the IAT are more broadly connected than previously thought. PMID:25133639

  12. Reducing implicit racial preferences: II. Intervention effectiveness across time.

    PubMed

    Lai, Calvin K; Skinner, Allison L; Cooley, Erin; Murrar, Sohad; Brauer, Markus; Devos, Thierry; Calanchini, Jimmy; Xiao, Y Jenny; Pedram, Christina; Marshburn, Christopher K; Simon, Stefanie; Blanchar, John C; Joy-Gaba, Jennifer A; Conway, John; Redford, Liz; Klein, Rick A; Roussos, Gina; Schellhaas, Fabian M H; Burns, Mason; Hu, Xiaoqing; McLean, Meghan C; Axt, Jordan R; Asgari, Shaki; Schmidt, Kathleen; Rubinstein, Rachel; Marini, Maddalena; Rubichi, Sandro; Shin, Jiyun-Elizabeth L; Nosek, Brian A

    2016-08-01

    Implicit preferences are malleable, but does that change last? We tested 9 interventions (8 real and 1 sham) to reduce implicit racial preferences over time. In 2 studies with a total of 6,321 participants, all 9 interventions immediately reduced implicit preferences. However, none were effective after a delay of several hours to several days. We also found that these interventions did not change explicit racial preferences and were not reliably moderated by motivations to respond without prejudice. Short-term malleability in implicit preferences does not necessarily lead to long-term change, raising new questions about the flexibility and stability of implicit preferences. (PsycINFO Database Record PMID:27454041

  13. The implicit structure of positive characteristics.

    PubMed

    Haslam, Nick; Bain, Paul; Neal, David

    2004-04-01

    The implicit structure of positive character traits was examined in two studies of 190 and 100 undergraduates. Participants judged the pairwise covariation or semantic similarity of 42 positive characteristics using a sorting or a rating task. Characteristics were drawn from a new classification of strengths and virtues, the Five-Factor Model, and a taxonomy of values. Participants showed consistent patterns of perceived association among the characteristics across the study conditions. Multidimensional scaling yielded three consistent dimensions underlying these judgments ("warmth vs. self-control," "vivacity vs. decency," and "wisdom vs. power"). Cluster analyses yielded six consistent groupings-"self-control," "love," "wisdom," "drive," "vivacity," and "collaboration"-that corresponded only moderately to the virtue classification. All three taxonomies were systematically related to this implicit structure, but none captured it satisfactorily on its own. Revisions to positive psychology's classification of strengths are proposed. PMID:15070480

  14. The neural correlates of implicit theory violation.

    PubMed

    Xu, Xiaowen; Plaks, Jason E

    2015-08-01

    The present study examined whether perceivers' implicit theories about the fixedness of intelligence would modulate neurophysiological responses to stereotype-violating and stereotype-confirming information. Brain activity was recorded using EEG as participants read a series of stereotype-confirming or stereotype-violating behaviors performed by a target character. Compared to incremental theorists (who believe that intelligence is malleable), entity theorists (who believe that intelligence is fixed) displayed more pronounced N400 responses to stereotype-violating behaviors. In contrast, incremental theorists exhibited more pronounced N400 responses than entity theorists to stereotype-confirming behaviors. These results shed light on basic processes in Person Memory by suggesting that perceivers make a distinction at the neurocognitive level between stereotype violations versus implicit theory violations. PMID:25650726

  15. Extrapolated implicit-explicit time stepping.

    SciTech Connect

    Constantinescu, E. M.; Sandu, A.; Mathematics and Computer Science; Virginia Polytechnic Inst. and State Univ.

    2010-01-01

    This paper constructs extrapolated implicit-explicit time stepping methods that allow one to efficiently solve problems with both stiff and nonstiff components. The proposed methods are based on Euler steps and can provide very high order discretizations of ODEs, index-1 DAEs, and PDEs in the method-of-lines framework. Implicit-explicit schemes based on extrapolation are simple to construct, easy to implement, and straightforward to parallelize. This work establishes the existence of perturbed asymptotic expansions of global errors, explains the convergence orders of these methods, and studies their linear stability properties. Numerical results with stiff ODE, DAE, and PDE test problems confirm the theoretical findings and illustrate the potential of these methods to solve multiphysics multiscale problems.

  16. Implicit Extrapolation Methods for Variable Coefficient Problems

    NASA Technical Reports Server (NTRS)

    Jung, M.; Ruede, U.

    1996-01-01

    Implicit extrapolation methods for the solution of partial differential equations are based on applying the extrapolation principle indirectly. Multigrid tau-extrapolation is a special case of this idea. In the context of multilevel finite element methods, an algorithm of this type can be used to raise the approximation order, even when the meshes are nonuniform or locally refined. Here previous results are generalized to the variable coefficient case and thus become applicable for nonlinear problems. The implicit extrapolation multigrid algorithm converges to the solution of a higher order finite element system. This is obtained without explicitly constructing higher order stiffness matrices but by applying extrapolation in a natural form within the algorithm. The algorithm requires only a small change of a basic low order multigrid method.

  17. Implicit Multibody Penalty-BasedDistributed Contact.

    PubMed

    Xu, Hongyi; Zhao, Yili; Barbic, Jernej

    2014-09-01

    The penalty method is a simple and popular approach to resolving contact in computer graphics and robotics. Penalty-based contact, however, suffers from stability problems due to the highly variable and unpredictable net stiffness, and this is particularly pronounced in simulations with time-varying distributed geometrically complex contact. We employ semi-implicit integration, exact analytical contact gradients, symbolic Gaussian elimination and a SVD solver to simulate stable penalty-based frictional contact with large, time-varying contact areas, involving many rigid objects and articulated rigid objects in complex conforming contact and self-contact. We also derive implicit proportional-derivative control forces for real-time control of articulated structures with loops. We present challenging contact scenarios such as screwing a hexbolt into a hole, bowls stacked in perfectly conforming configurations, and manipulating many objects using actively controlled articulated mechanisms in real time. PMID:26357376

  18. Orbit-averaged implicit particle codes

    NASA Astrophysics Data System (ADS)

    Cohen, B. I.; Freis, R. P.; Thomas, V.

    1982-03-01

    The merging of orbit-averaged particle code techniques with recently developed implicit methods to perform numerically stable and accurate particle simulations are reported. Implicitness and orbit averaging can extend the applicability of particle codes to the simulation of long time-scale plasma physics phenomena by relaxing time-step and statistical constraints. Difference equations for an electrostatic model are presented, and analyses of the numerical stability of each scheme are given. Simulation examples are presented for a one-dimensional electrostatic model. Schemes are constructed that are stable at large-time step, require fewer particles, and, hence, reduce input-output and memory requirements. Orbit averaging, however, in the unmagnetized electrostatic models tested so far is not as successful as in cases where there is a magnetic field. Methods are suggested in which orbit averaging should achieve more significant improvements in code efficiency.

  19. Implicitly modelled stratigraphic surfaces using generalized interpolation

    NASA Astrophysics Data System (ADS)

    Hillier, Michael; de Kemp, Eric; Schetselaar, Ernst

    2016-06-01

    Stratigraphic surfaces implicitly modelled using a generalized interpolation approach in various geological settings is presented to demonstrate its modelling capabilities and limitations. The generalized interpolation approach provides a useful mathematical framework in modelling continuous surfaces from scattered data consisting of the following geological constraints: contact locations and planar orientations. Examples are presented to show the effectiveness of the method in generating plausible representations of geological structures in sparse data environments. One of the major advantages of implicit surface modelling has long been claimed as its ability to model geometries with arbitrary topology. It is, however, demonstrated that this is in fact a disadvantage in robustly generating geologically realistic surfaces in structurally complex domains with a known topology.

  20. An implicit fast Fourier transform method for integration of the time dependent Schrodinger equation

    SciTech Connect

    Riley, M.E.; Ritchie, A.B.

    1997-12-31

    One finds that the conventional exponentiated split operator procedure is subject to difficulties when solving the time-dependent Schrodinger equation for Coulombic systems. By rearranging the kinetic and potential energy terms in the temporal propagator of the finite difference equations, one can find a propagation algorithm for three dimensions that looks much like the Crank-Nicholson and alternating direction implicit methods for one- and two-space-dimensional partial differential equations. The authors report investigations of this novel implicit split operator procedure. The results look promising for a purely numerical approach to certain electron quantum mechanical problems. A charge exchange calculation is presented as an example of the power of the method.

  1. Group implicit concurrent algorithms in nonlinear structural dynamics

    NASA Technical Reports Server (NTRS)

    Ortiz, M.; Sotelino, E. D.

    1989-01-01

    During the 70's and 80's, considerable effort was devoted to developing efficient and reliable time stepping procedures for transient structural analysis. Mathematically, the equations governing this type of problems are generally stiff, i.e., they exhibit a wide spectrum in the linear range. The algorithms best suited to this type of applications are those which accurately integrate the low frequency content of the response without necessitating the resolution of the high frequency modes. This means that the algorithms must be unconditionally stable, which in turn rules out explicit integration. The most exciting possibility in the algorithms development area in recent years has been the advent of parallel computers with multiprocessing capabilities. So, this work is mainly concerned with the development of parallel algorithms in the area of structural dynamics. A primary objective is to devise unconditionally stable and accurate time stepping procedures which lend themselves to an efficient implementation in concurrent machines. Some features of the new computer architecture are summarized. A brief survey of current efforts in the area is presented. A new class of concurrent procedures, or Group Implicit algorithms is introduced and analyzed. The numerical simulation shows that GI algorithms hold considerable promise for application in coarse grain as well as medium grain parallel computers.

  2. An advanced implicit solver for MHD

    NASA Astrophysics Data System (ADS)

    Udrea, Bogdan

    A new implicit algorithm has been developed for the solution of the time-dependent, viscous and resistive single fluid magnetohydrodynamic (MHD) equations. The algorithm is based on an approximate Riemann solver for the hyperbolic fluxes and central differencing applied on a staggered grid for the parabolic fluxes. The algorithm employs a locally aligned coordinate system that allows the solution to the Riemann problems to be solved in a natural direction, normal to cell interfaces. The result is an original scheme that is robust and reduces the complexity of the flux formulas. The evaluation of the parabolic fluxes is also implemented using a locally aligned coordinate system, this time on the staggered grid. The implicit formulation employed by WARP3 is a two level scheme that was applied for the first time to the single fluid MHD model. The flux Jacobians that appear in the implicit scheme are evaluated numerically. The linear system that results from the implicit discretization is solved using a robust symmetric Gauss-Seidel method. The code has an explicit mode capability so that implementation and test of new algorithms or new physics can be performed in this simpler mode. Last but not least the code was designed and written to run on parallel computers so that complex, high resolution runs can be per formed in hours rather than days. The code has been benchmarked against analytical and experimental gas dynamics and MHD results. The benchmarks consisted of one-dimensional Riemann problems and diffusion dominated problems, two-dimensional supersonic flow over a wedge, axisymmetric magnetoplasmadynamic (MPD) thruster simulation and three-dimensional supersonic flow over intersecting wedges and spheromak stability simulation. The code has been proven to be robust and the results of the simulations showed excellent agreement with analytical and experimental results. Parallel performance studies showed that the code performs as expected when run on parallel

  3. Implicit and explicit ethnocentrism: revisiting the ideologies of prejudice.

    PubMed

    Cunningham, William A; Nezlek, John B; Banaji, Mahzarin R

    2004-10-01

    Two studies investigated relationships among individual differences in implicit and explicit prejudice, right-wing ideology, and rigidity in thinking. The first study examined these relationships focusing on White Americans' prejudice toward Black Americans. The second study provided the first test of implicit ethnocentrism and its relationship to explicit ethnocentrism by studying the relationship between attitudes toward five social groups. Factor analyses found support for both implicit and explicit ethnocentrism. In both studies, mean explicit attitudes toward out groups were positive, whereas implicit attitudes were negative, suggesting that implicit and explicit prejudices are distinct; however, in both studies, implicit and explicit attitudes were related (r = .37, .47). Latent variable modeling indicates a simple structure within this ethnocentric system, with variables organized in order of specificity. These results lead to the conclusion that (a) implicit ethnocentrism exists and (b) it is related to and distinct from explicit ethnocentrism. PMID:15466605

  4. Intergroup anxiety effects on implicit racial evaluation and stereotyping.

    PubMed

    Amodio, David M; Hamilton, Holly K

    2012-12-01

    How does intergroup anxiety affect the activation of implicit racial evaluations and stereotypes? Given the common basis of social anxiety and implicit evaluative processes in memory systems linked to classical conditioning and affect, we predicted that intergroup anxiety would amplify implicit negative racial evaluations. Implicit stereotyping, which is associated primarily with semantic memory systems, was not expected to increase as a function of intergroup anxiety. This pattern was observed among White participants preparing to interact with Black partners, but not those preparing to interact with White partners. These findings shed new light on how anxiety, often elicited in real-life intergroup interactions, can affect the operation of implicit racial biases, suggesting that intergroup anxiety has more direct implications for affective and evaluative forms of implicit bias than for implicit stereotyping. These findings also support a memory-systems model of the interplay between emotion and cognition in the context of social behavior. PMID:22775128

  5. Non-LTE models for synthetic spectra of type Ia supernovae. III. An accelerated lambda-iteration procedure for the mutual interaction of strong spectral lines in SN Ia models with and without energy deposition

    NASA Astrophysics Data System (ADS)

    Pauldrach, A. W. A.; Hoffmann, T. L.; Hultzsch, P. J. N.

    2014-09-01

    . Thus, hydrodynamic explosion models and realistic model atmospheres that take into account the strong deviation from local thermodynamic equilibrium (LTE) are necessary for the synthesis and analysis of the spectra. In this regard one of the biggest challenges we have found in modeling the radiative transfer in SN Ia is the fact that the radiative energy in the UV has to be transferred only via spectral lines into the optical regime to be able to leave the ejecta. However, convergence of the model toward a state where this is possible is impaired when using the standard procedures. We report on improvements in our approach of computing synthetic spectra for SN Ia with respect to (i) an improved and sophisticated treatment of many thousands of strong lines that interact intricately with the "pseudo-continuum" formed entirely by Doppler-shifted spectral lines; (ii) an improved and expanded atomic database; and (iii) the inclusion of energy deposition within the ejecta arising from the radioactive decay of mostly 56Ni and 56Co. Results: We show that an ALI procedure we have developed for the mutual interaction of strong spectral lines appearing in the atmospheres of SNe Ia solves the long-standing problem of transferring the radiative energy from the UV into the optical regime. Our new method thus constitutes a foundation for more refined models, such as those including energy deposition. In this regard we furthermore show synthetic spectra obtained with various methods adopted for the released energy and compare them with observations. We discuss in detail applications of the diagnostic technique by example of a standard type Ia supernova, where the comparison of calculated and observed spectra revealed that in the early phases the consideration of the energy deposition within the spectrum-forming regions of the ejecta does not qualitatively alter the shape of the emergent spectra. Conclusions: The results of our investigation lead to an improved understanding of how the

  6. Specific Deficit in Implicit Motor Sequence Learning following Spinal Cord Injury

    PubMed Central

    Bloch, Ayala; Tamir, Dror; Vakil, Eli; Zeilig, Gabi

    2016-01-01

    Background Physical and psychosocial rehabilitation following spinal cord injury (SCI) leans heavily on learning and practicing new skills. However, despite research relating motor sequence learning to spinal cord activity and clinical observations of impeded skill-learning after SCI, implicit procedural learning following spinal cord damage has not been examined. Objective To test the hypothesis that spinal cord injury (SCI) in the absence of concomitant brain injury is associated with a specific implicit motor sequence learning deficit that cannot be explained by depression or impairments in other cognitive measures. Methods Ten participants with SCI in T1-T11, unharmed upper limb motor and sensory functioning, and no concomitant brain injury were compared to ten matched control participants on measures derived from the serial reaction time (SRT) task, which was used to assess implicit motor sequence learning. Explicit generation of the SRT sequence, depression, and additional measures of learning, memory, and intelligence were included to explore the source and specificity of potential learning deficits. Results There was no between-group difference in baseline reaction time, indicating that potential differences between the learning curves of the two groups could not be attributed to an overall reduction in response speed in the SCI group. Unlike controls, the SCI group showed no decline in reaction time over the first six blocks of the SRT task and no advantage for the initially presented sequence over the novel interference sequence. Meanwhile, no group differences were found in explicit learning, depression, or any additional cognitive measures. Conclusions The dissociation between impaired implicit learning and intact declarative memory represents novel empirical evidence of a specific implicit procedural learning deficit following SCI, with broad implications for rehabilitation and adjustment. PMID:27355834

  7. Fully implicit adaptive mesh refinement MHD algorithm

    NASA Astrophysics Data System (ADS)

    Philip, Bobby

    2005-10-01

    In the macroscopic simulation of plasmas, the numerical modeler is faced with the challenge of dealing with multiple time and length scales. The former results in stiffness due to the presence of very fast waves. The latter requires one to resolve the localized features that the system develops. Traditional approaches based on explicit time integration techniques and fixed meshes are not suitable for this challenge, as such approaches prevent the modeler from using realistic plasma parameters to keep the computation feasible. We propose here a novel approach, based on implicit methods and structured adaptive mesh refinement (SAMR). Our emphasis is on both accuracy and scalability with the number of degrees of freedom. To our knowledge, a scalable, fully implicit AMR algorithm has not been accomplished before for MHD. As a proof-of-principle, we focus on the reduced resistive MHD model as a basic MHD model paradigm, which is truly multiscale. The approach taken here is to adapt mature physics-based technologyootnotetextL. Chac'on et al., J. Comput. Phys. 178 (1), 15- 36 (2002) to AMR grids, and employ AMR-aware multilevel techniques (such as fast adaptive composite --FAC-- algorithms) for scalability. We will demonstrate that the concept is indeed feasible, featuring optimal scalability under grid refinement. Results of fully-implicit, dynamically-adaptive AMR simulations will be presented on a variety of problems.

  8. Toward a meaningful metric of implicit prejudice.

    PubMed

    Blanton, Hart; Jaccard, James; Strauts, Erin; Mitchell, Gregory; Tetlock, Philip E

    2015-09-01

    [Correction Notice: An Erratum for this article was reported in Vol 100(5) of Journal of Applied Psychology (see record 2015-40760-001). there are errors in some of the values listed in Table 6 that do not alter any of the conclusions or substantive statements in the original article. The corrected portion of Table 6 is in the correction. The positive intercepts in this table represent the estimated IAT score when the criterion has a value of zero (suggesting attitudinal neutrality), except in the equation examining voter preference in Greenwald et al. (2009), where the intercept estimated the IAT score of Obama voters.] The modal distribution of the Implicit Association Test (IAT) is commonly interpreted as showing high levels of implicit prejudice among Americans. These interpretations have fueled calls for changes in organizational and legal practices, but such applications are problematic because the IAT is scored on an arbitrary psychological metric. The present research was designed to make the IAT metric less arbitrary by determining the scores on IAT measures that are associated with observable racial or ethnic bias. By reexamining data from published studies, we found evidence that the IAT metric is "right biased," such that individuals who are behaviorally neutral tend to have positive IAT scores. Current scoring conventions fail to take into account these dynamics and can lead to faulty inferences about the prevalence of implicit prejudice. PMID:25602125

  9. Implicit constitutive relations for nonlinear magnetoelastic bodies

    PubMed Central

    Bustamante, R.; Rajagopal, K. R.

    2015-01-01

    Implicit constitutive relations that characterize the response of elastic bodies have greatly enhanced the arsenal available at the disposal of the analyst working in the field of elasticity. This class of models were recently extended to describe electroelastic bodies by the present authors. In this paper, we extend the development of implicit constitutive relations to describe the behaviour of elastic bodies that respond to magnetic stimuli. The models that are developed provide a rational way to describe phenomena that have hitherto not been adequately described by the classical models that are in place. After developing implicit constitutive relations for magnetoelastic bodies undergoing large deformations, we consider the linearization of the models within the context of small displacement gradients. We then use the linearized model to describe experimentally observed phenomena which the classical linearized magnetoelastic models are incapable of doing. We also solve several boundary value problems within the context of the models that are developed: extension and shear of a slab, and radial inflation and extension of a cylinder. PMID:25792968

  10. A conservative implicit finite difference algorithm for the unsteady transonic full potential equation

    NASA Technical Reports Server (NTRS)

    Steger, J. L.; Caradonna, F. X.

    1980-01-01

    An implicit finite difference procedure is developed to solve the unsteady full potential equation in conservation law form. Computational efficiency is maintained by use of approximate factorization techniques. The numerical algorithm is first order in time and second order in space. A circulation model and difference equations are developed for lifting airfoils in unsteady flow; however, thin airfoil body boundary conditions have been used with stretching functions to simplify the development of the numerical algorithm.

  11. Implicit memory functioning in schizophrenia: explaining inconsistent findings of word stem completion tasks.

    PubMed

    Soler, María José; Ruiz, Juan Carlos; Dasí, Carmen; Fuentes-Durá, Inma

    2015-03-30

    The definitive implicit memory profile of schizophrenia is yet to be clarified. Methodological differences between studies could be the reason for the inconsistent findings reported. In this study, we have examined implicit memory functioning using a word stem completion task. In addition, we have addressed methodological issues related with lexical and perceptual stimuli characteristics, and with the strategy used to calculate priming scores. Our data show similar performance values in schizophrenic patients and healthy controls. Furthermore, we have not detected significant differences in priming between the two groups, even when this parameter was calculated using three different procedures. These results are in line with those we have reported previously using the same stimuli in a word fragment completion task. Considered as a whole, our research suggests that implicit memory functioning in schizophrenia is unimpaired when assessed using word fragment or stem completion tasks. In light of this, future studies should follow standardized criteria to assess implicit memory when the sensitivity of the task employed is essential for identifying potential memory deficits in schizophrenia. PMID:25667118

  12. Global Similarity Predicts Dissociation of Classification and Recognition: Evidence Questioning the Implicit-Explicit Learning Distinction in Amnesia

    ERIC Educational Resources Information Center

    Jamieson, Randall K.; Holmes, Signy; Mewhort, D. J. K.

    2010-01-01

    Dissociation of classification and recognition in amnesia is widely taken to imply 2 functional systems: an implicit procedural-learning system that is spared in amnesia and an explicit episodic-learning system that is compromised. We argue that both tasks reflect the global similarity of probes to memory. In classification, subjects sort…

  13. Metrical Presentation Boosts Implicit Learning of Artificial Grammar

    PubMed Central

    Selchenkova, Tatiana; François, Clément; Schön, Daniele; Corneyllie, Alexandra; Perrin, Fabien; Tillmann, Barbara

    2014-01-01

    The present study investigated whether a temporal hierarchical structure favors implicit learning. An artificial pitch grammar implemented with a set of tones was presented in two different temporal contexts, notably with either a strongly metrical structure or an isochronous structure. According to the Dynamic Attending Theory, external temporal regularities can entrain internal oscillators that guide attention over time, allowing for temporal expectations that influence perception of future events. Based on this framework, it was hypothesized that the metrical structure provides a benefit for artificial grammar learning in comparison to an isochronous presentation. Our study combined behavioral and event-related potential measurements. Behavioral results demonstrated similar learning in both participant groups. By contrast, analyses of event-related potentials showed a larger P300 component and an earlier N2 component for the strongly metrical group during the exposure phase and the test phase, respectively. These findings suggests that the temporal expectations in the strongly metrical condition helped listeners to better process the pitch dimension, leading to improved learning of the artificial grammar. PMID:25372147

  14. A Fully-Implicit, Ion-Electron, Vlasov-Poisson Algorithm

    NASA Astrophysics Data System (ADS)

    Taitano, William; Knoll, Dana; Chacon, Luis

    2010-11-01

    The Jacobian-Free-Newton-Krylov method (JFNK) is an advanced non- linear alogorithm that allows solution to a coupled systems of non-linear equations [1]. We put forth a new JFNK-based implicit plasma simulation algorithm. We have studied this algorithm within the context of a two-species Vlasov-Poisson system where the Vlasov equations are solved in an Eulerian frame [2]. We have investigated the route of non-linear-elimination/kinetic- enslavement to reduce the size of block Jacobian matrix in order to solve the field-kinetic system implicitly. The non-linear- elimination/kinetic-enslavement technique allows reduction in the size of non-linear system but still retains high order temporal accuracy and strong non-linear coupling. Our new algorithm make implicit time-dependent, coupled, field-kinetic systems more attractive. As will be shown, a fully implicit run was able to achieve 22 times speed-up compared to the explicit run for our ion-acoustic-showckwave simulation [2].[4pt] [1] D.A. Knoll and D.E. Keyes, J. Comput. Phys. vol. 193 (2004)[0pt] [2] W.T. Taitano, Masters Thesis, Nuclear Engineering, University of Idaho (2010)

  15. The discrepancy between implicit and explicit attitudes in predicting disinhibited eating.

    PubMed

    Goldstein, Stephanie P; Forman, Evan M; Meiran, Nachshon; Herbert, James D; Juarascio, Adrienne S; Butryn, Meghan L

    2014-01-01

    Disinhibited eating (i.e., the tendency to overeat, despite intentions not to do so, in the presence of palatable foods or other cues such as emotional stress) is strongly linked with obesity and appears to be associated with both implicit (automatic) and explicit (deliberative) food attitudes. Prior research suggests that a large discrepancy between implicit and explicit food attitudes may contribute to greater levels of disinhibited eating; however this theory has not been directly tested. The current study examined whether the discrepancy between implicit and explicit attitudes towards chocolate could predict both lab-based and self-reported disinhibited eating of chocolate. Results revealed that, whereas neither implicit nor explicit attitudes alone predicted disinhibited eating, absolute attitude discrepancy positively predicted chocolate consumption. Impulsivity moderated this effect, such that discrepancy was less predictive of disinhibited eating for those who exhibited lower levels of impulsivity. The results align with the meta-cognitive model to indicate that attitude discrepancy may be involved in overeating. PMID:24411770

  16. 3D Model Segmentation and Representation with Implicit Polynomials

    NASA Astrophysics Data System (ADS)

    Zheng, Bo; Takamatsu, Jun; Ikeuchi, Katsushi

    When large-scale and complex 3D objects are obtained by range finders, it is often necessary to represent them by algebraic surfaces for such purposes as data compression, multi-resolution, noise elimination, and 3D recognition. Representing the 3D data with algebraic surfaces of an implicit polynomial (IP) has proved to offer the advantages that IP representation is capable of encoding geometric properties easily with desired smoothness, few parameters, algebraic/geometric invariants, and robustness to noise and missing data. Unfortunately, generating a high-degree IP surface for a whole complex 3D shape is impossible because of high computational cost and numerical instability. In this paper we propose a 3D segmentation method based on a cut-and-merge approach. Two cutting procedures adopt low-degree IPs to divide and fit the surface segments simultaneously, while avoiding generating high-curved segments. A merging procedure merges the similar adjacent segments to avoid over-segmentation. To prove the effectiveness of this segmentation method, we open up some new vistas for 3D applications such as 3D matching, recognition, and registration.

  17. Implicit and Explicit Timing in Oculomotor Control

    PubMed Central

    Ameqrane, Ilhame; Pouget, Pierre; Wattiez, Nicolas; Carpenter, Roger; Missal, Marcus

    2014-01-01

    The passage of time can be estimated either explicitly, e.g. before leaving home in the morning, or implicitly, e.g. when catching a flying ball. In the present study, the latency of saccadic eye movements was used to evaluate differences between implicit and explicit timing. Humans were required to make a saccade between a central and a peripheral position on a computer screen. The delay between the extinction of a central target and the appearance of an eccentric target was the independent variable that could take one out of four different values (400, 900, 1400 or 1900 ms). In target trials, the delay period lasted for one of the four durations randomly. At the end of the delay, a saccade was initiated by the appearance of an eccentric target. Cue&target trials were similar to target trials but the duration of the delay was visually cued. In probe trials, the duration of the upcoming delay was cued, but there was no eccentric target and subjects had to internally generate a saccade at the estimated end of the delay. In target and cue&target trials, the mean and variance of latency distributions decreased as delay duration increased. In cue&target trials latencies were shorter. In probe trials, the variance increased with increasing delay duration and scalar variability was observed. The major differences in saccadic latency distributions were observed between visually-guided (target and cue&target trials) and internally-generated saccades (probe trials). In target and cue&target trials the timing of the response was implicit. In probe trials, the timing of the response was internally-generated and explicitly based on the duration of the visual cue. Scalar timing was observed only during probe trials. This study supports the hypothesis that there is no ubiquitous timing system in the brain but independent timing processes active depending on task demands. PMID:24728140

  18. Neural Patterns of the Implicit Association Test

    PubMed Central

    Healy, Graham F.; Boran, Lorraine; Smeaton, Alan F.

    2015-01-01

    The Implicit Association Test (IAT) is a reaction time based categorization task that measures the differential associative strength between bipolar targets and evaluative attribute concepts as an approach to indexing implicit beliefs or biases. An open question exists as to what exactly the IAT measures, and here EEG (Electroencephalography) has been used to investigate the time course of ERPs (Event-related Potential) indices and implicated brain regions in the IAT. IAT-EEG research identifies a number of early (250–450 ms) negative ERPs indexing early-(pre-response) processing stages of the IAT. ERP activity in this time range is known to index processes related to cognitive control and semantic processing. A central focus of these efforts has been to use IAT-ERPs to delineate the implicit and explicit factors contributing to measured IAT effects. Increasing evidence indicates that cognitive control (and related top-down modulation of attention/perceptual processing) may be components in the effective measurement of IAT effects, as factors such as physical setting or task instruction can change an IAT measurement. In this study we further implicate the role of proactive cognitive control and top-down modulation of attention/perceptual processing in the IAT-EEG. We find statistically significant relationships between D-score (a reaction-time based measure of the IAT-effect) and early ERP-time windows, indicating where more rapid word categorizations driving the IAT effect are present, they are at least partly explainable by neural activity not significantly correlated with the IAT measurement itself. Using LORETA, we identify a number of brain regions driving these ERP-IAT relationships notably involving left-temporal, insular, cingulate, medial frontal and parietal cortex in time regions corresponding to the N2- and P3-related activity. The identified brain regions involved with reduced reaction times on congruent blocks coincide with those of previous studies

  19. Implicit and Explicit Learning in Individuals with Agrammatic Aphasia

    PubMed Central

    Schuchard, Julia; Thompson, Cynthia K.

    2013-01-01

    Implicit learning is a process of acquiring knowledge that occurs without conscious awareness of learning, whereas explicit learning involves the use of overt strategies. To date, research related to implicit learning following stroke has been largely restricted to the motor domain and has rarely addressed implications for language. The present study investigated implicit and explicit learning of an auditory word sequence in 10 individuals with stroke-induced agrammatic aphasia and 18 healthy age-matched participants using an adaptation of the Serial Reaction Time task. Individuals with aphasia showed significant learning under implicit, but not explicit, conditions, whereas age-matched participants learned under both conditions. These results suggest significant implicit learning ability in agrammatic aphasia. Furthermore, results of an auditory sentence span task indicated working memory deficits in individuals with agrammatic aphasia, which are discussed in relation to explicit and implicit learning processes. PMID:23532578

  20. Predicting film genres with implicit ideals.

    PubMed

    Olney, Andrew McGregor

    2012-01-01

    We present a new approach to defining film genre based on implicit ideals. When viewers rate the likability of a film, they indirectly express their ideal of what a film should be. Across six studies we investigate the category structure that emerges from likability ratings and the category structure that emerges from the features of film. We further compare these data-driven category structures with human annotated film genres. We conclude that film genres are structured more around ideals than around features of film. This finding lends experimental support to the notion that film genres are set of shifting, fuzzy, and highly contextualized psychological categories. PMID:23423823

  1. Predicting Film Genres with Implicit Ideals

    PubMed Central

    Olney, Andrew McGregor

    2013-01-01

    We present a new approach to defining film genre based on implicit ideals. When viewers rate the likability of a film, they indirectly express their ideal of what a film should be. Across six studies we investigate the category structure that emerges from likability ratings and the category structure that emerges from the features of film. We further compare these data-driven category structures with human annotated film genres. We conclude that film genres are structured more around ideals than around features of film. This finding lends experimental support to the notion that film genres are set of shifting, fuzzy, and highly contextualized psychological categories. PMID:23423823

  2. Development of Implicit and Explicit Category Learning

    PubMed Central

    Huang-Pollock, Cynthia L.; Maddox, W. Todd; Karalunas, Sarah L.

    2011-01-01

    We present two studies that examine developmental differences in the implicit and explicit acquisition of category knowledge. College-attending adults consistently outperformed school-aged children on two separate information integration paradigms due to children’s more frequent use of an explicit rule-based strategy. Accuracy rates were also higher for adults on a unidimensional rule-based task due to children’s more frequent use of the irrelevant dimension to guide their behavior. Results across these two studies suggest that the ability to learn categorization structures may be dependent upon a child’s ability to inhibit output from the explicit system. PMID:21377688

  3. Adaptive Implicit Non-Equilibrium Radiation Diffusion

    SciTech Connect

    Philip, Bobby; Wang, Zhen; Berrill, Mark A; Rodriguez Rodriguez, Manuel; Pernice, Michael

    2013-01-01

    We describe methods for accurate and efficient long term time integra- tion of non-equilibrium radiation diffusion systems: implicit time integration for effi- cient long term time integration of stiff multiphysics systems, local control theory based step size control to minimize the required global number of time steps while control- ling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton-Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent solver convergence.

  4. Acceleration of convergence by shifting the spectrum of implicit finite difference operators associated with the equations of gas dynamics

    NASA Technical Reports Server (NTRS)

    Cheer, A.; Saleem, M.

    1991-01-01

    Eigensystem analysis techniques are applied to finite difference formulations of the Navier-Stokes equations in one dimension. Spectra of the resulting implicit difference operators are computed. The largest eigenvalues are calculated by using a combination of the Frechet derivative of the operators and Arnoldi's method. The accuracy of Arnoldi's method is tested by comparing the rate of convergence of the iterative method with the dominant eigenvalue of the original iteration matrix. On the basis of the pattern of eigenvalue distributions for various flow configurations, a shifting of the implicit operators in question is devised. This procedure has improved the rates of convergence of CFD codes by 20 - 50 percent.

  5. Time-accurate analysis of nonequilibrium gas-particle mixtures using upwind/implicit finite-volume methodology

    SciTech Connect

    Hosangadi, A.; Sinha, N.; Dash, S.M. )

    1992-01-01

    A new Eulerian particulate solver whose numerical formulation is compatible with the numerics in state-of-the-art finite-volume upwind/implicit gas dynamic computer codes is presented. The heat transfer, drag, thermodynamic, and phase-change procedures in this code are derived from earlier, well established data fits and procedures. Performance for numerous flow problems with one- and two-way coupling is quite good. The solutions are nonoscillatory and robust and conserve flux balances very well. 18 refs.

  6. Disentangling Rheumatoid Arthritis Patients' Implicit and Explicit Attitudes toward Methotrexate.

    PubMed

    Linn, Annemiek J; Vandeberg, Lisa; Wennekers, Annemarie M; Vervloet, Marcia; van Dijk, Liset; van den Bemt, Bart J F

    2016-01-01

    Medication non-adherence is a major public health problem that has been termed an 'invisible epidemic.' Non-adherence is not only associated with negative clinical consequences but can also result in substantial healthcare costs. Up to now, effective adherence interventions are scarce and a more comprehensive model of adherence determinants is required to target the determinants for not taking the medication as prescribed. Current approaches only included explicit attitudes such as self-reported evaluations of medication as determinants, neglecting the role of associative processes that shape implicit attitudes. Implicit processes can predict daily behavior more accurately than explicit attitudes. Our aim is to assess explicit and implicit attitudes toward medication and explore the relation with beliefs, adherence and clinical (laboratory) outcomes in chronically ill patients. Fifty two Rheumatic Arthritis (RA) patients' attitudes toward Methotrexate (MTX) were explicitly (self-reported) and implicitly (Single-Category Implicit Association Test) assessed and related to the Beliefs about Medicine Questionnaire, the Compliance Questionnaire on Rheumatology and laboratory parameters [Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP)]. Results show that explicit attitudes were positive and health-related. Implicit attitudes were, however, negative and sickness-related. Half of the patients displayed explicitly positive but implicitly negative attitudes. Explicit attitudes were positively related to ESR. A positive relationship between implicit attitudes and disease duration was observed. In this study, we have obtained evidence suggesting that the measurement of implicit attitudes and associations provides different information than explicit, self-reported attitudes toward medication. Since patients' implicit attitudes deviated from explicit attitudes, we can conclude that the relationship between implicit attitudes and medication adherence is worthwhile

  7. Disentangling Rheumatoid Arthritis Patients’ Implicit and Explicit Attitudes toward Methotrexate

    PubMed Central

    Linn, Annemiek J.; Vandeberg, Lisa; Wennekers, Annemarie M.; Vervloet, Marcia; van Dijk, Liset; van den Bemt, Bart J. F.

    2016-01-01

    Medication non-adherence is a major public health problem that has been termed an ‘invisible epidemic.’ Non-adherence is not only associated with negative clinical consequences but can also result in substantial healthcare costs. Up to now, effective adherence interventions are scarce and a more comprehensive model of adherence determinants is required to target the determinants for not taking the medication as prescribed. Current approaches only included explicit attitudes such as self-reported evaluations of medication as determinants, neglecting the role of associative processes that shape implicit attitudes. Implicit processes can predict daily behavior more accurately than explicit attitudes. Our aim is to assess explicit and implicit attitudes toward medication and explore the relation with beliefs, adherence and clinical (laboratory) outcomes in chronically ill patients. Fifty two Rheumatic Arthritis (RA) patients’ attitudes toward Methotrexate (MTX) were explicitly (self-reported) and implicitly (Single-Category Implicit Association Test) assessed and related to the Beliefs about Medicine Questionnaire, the Compliance Questionnaire on Rheumatology and laboratory parameters [Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP)]. Results show that explicit attitudes were positive and health-related. Implicit attitudes were, however, negative and sickness-related. Half of the patients displayed explicitly positive but implicitly negative attitudes. Explicit attitudes were positively related to ESR. A positive relationship between implicit attitudes and disease duration was observed. In this study, we have obtained evidence suggesting that the measurement of implicit attitudes and associations provides different information than explicit, self-reported attitudes toward medication. Since patients’ implicit attitudes deviated from explicit attitudes, we can conclude that the relationship between implicit attitudes and medication adherence is

  8. Applications of implicit restarting in optimization and control Dan Sorensen

    SciTech Connect

    Sorensen, D.

    1996-12-31

    Implicit restarting is a technique for combining the implicitly shifted QR mechanism with a k-step Arnoldi or Lanczos factorization to obtain a truncated form of the implicitly shifted QR-iteration suitable for large scale eigenvalue problems. The software package ARPACK based upon this technique has been successfully used to solve large scale symmetric and nonsymmetric (generalized) eigenvalue problems arising from a variety of applications.

  9. Measuring Implicit Attitudes of 4-Year-Olds: The Preschool Implicit Association Test

    ERIC Educational Resources Information Center

    Cvencek, Dario; Greenwald, Anthony G.; Meltzoff, Andrew N.

    2011-01-01

    The Preschool Implicit Association Test (PSIAT) is an adaptation of an established social cognition measure (IAT) for use with preschool children. Two studies with 4-year-olds found that the PSIAT was effective in evaluating (a) attitudes toward commonly liked objects ("flowers"="good") and (b) gender attitudes ("girl"="good" or "boy"="good"). The…

  10. Applying an exemplar model to an implicit rule-learning task: Implicit learning of semantic structure.

    PubMed

    Chubala, Chrissy M; Johns, Brendan T; Jamieson, Randall K; Mewhort, D J K

    2016-06-01

    Studies of implicit learning often examine peoples' sensitivity to sequential structure. Computational accounts have evolved to reflect this bias. An experiment conducted by Neil and Higham [Neil, G. J., & Higham, P. A.(2012). Implicit learning of conjunctive rule sets: An alternative to artificial grammars. Consciousness and Cognition, 21, 1393-1400] points to limitations in the sequential approach. In the experiment, participants studied words selected according to a conjunctive rule. At test, participants discriminated rule-consistent from rule-violating words but could not verbalize the rule. Although the data elude explanation by sequential models, an exemplar model of implicit learning can explain them. To make the case, we simulate the full pattern of results by incorporating vector representations for the words used in the experiment, derived from the large-scale semantic space models LSA and BEAGLE, into an exemplar model of memory, MINERVA 2. We show that basic memory processes in a classic model of memory capture implicit learning of non-sequential rules, provided that stimuli are appropriately represented. PMID:26730987