The role of verbal and pictorial information in multimodal incidental acquisition of foreign language vocabulary

PubMed Central

Bisson, Marie-Josée; van Heuven, Walter J. B.; Conklin, Kathy; Tunney, Richard J.

2015-01-01

This study used eye tracking to investigate the allocation of attention to multimodal stimuli during an incidental learning situation, as well as its impact on subsequent explicit learning. Participants were exposed to foreign language (FL) auditory words on their own, in conjunction with written native language (NL) translations, or with both written NL translations and pictures. Incidental acquisition of FL words was assessed the following day through an explicit learning task where participants learned to recognize translation equivalents, as well as one week later through recall and translation recognition tests. Results showed higher accuracy scores in the explicit learning task for FL words presented with meaning during incidental learning, whether written meaning or both written meaning and picture, than for FL words presented auditorily only. However, participants recalled significantly more FL words after a week delay if they had been presented with a picture during incidental learning. In addition, the time spent looking at the pictures during incidental learning significantly predicted recognition and recall scores one week later. Overall, results demonstrated the impact of exposure to multimodal stimuli on subsequent explicit learning, as well as the important role that pictorial information can play in incidental vocabulary acquisition. PMID:25383918

Implicit and explicit self-esteem as concurrent predictors of suicidal ideation, depressive symptoms, and loneliness.

PubMed

Creemers, Daan H M; Scholte, Ron H J; Engels, Rutger C M E; Prinstein, Mitchell J; Wiers, Reinout W

2012-03-01

The aim of the present study was to examine whether explicit and implicit self-esteem, the interaction between these two constructs, and their discrepancy are associated with depressive symptoms, suicidal ideation, and loneliness. Participants were 95 young female adults (M = 21.2 years, SD = 1.88) enrolled in higher education. We administered the Name Letter Task to measure implicit self-esteem, and the Rosenberg self-esteem scale to assess explicit self-esteem. The results indicated that explicit but not implicit self-esteem was negatively associated with depressive symptoms, suicidal ideation, and loneliness. The interaction of implicit and explicit self-esteem was associated with suicidal ideation, indicating that participants with high implicit self-esteem combined with a low explicit self-esteem showed more suicidal ideation. Furthermore, the size of the discrepancy between implicit and explicit self-esteem was positively associated with depressive symptoms, suicidal ideation, and loneliness. In addition, results showed that the direction of the discrepancy is an important: damaged self-esteem (high implicit self-esteem combined with low explicit self-esteem) was consistently associated with increased levels of depressive symptoms, suicidal ideation, and loneliness, while defensive or fragile self-esteem (high explicit and low implicit self-esteem) was not. Together, these findings provide new insights into the relationship of implicit and explicit self-esteem with depressive symptoms, suicidal ideation, and loneliness. Copyright © 2011 Elsevier Ltd. All rights reserved.

The transfer of category knowledge by macaques (Macaca mulatta) and humans (Homo sapiens).

PubMed

Zakrzewski, Alexandria C; Church, Barbara A; Smith, J David

2018-02-01

Cognitive psychologists distinguish implicit, procedural category learning (stimulus-response associations learned outside declarative cognition) from explicit-declarative category learning (conscious category rules). These systems are dissociated by category learning tasks with either a multidimensional, information-integration (II) solution or a unidimensional, rule-based (RB) solution. In the present experiments, humans and two monkeys learned II and RB category tasks fostering implicit and explicit learning, respectively. Then they received occasional transfer trials-never directly reinforced-drawn from untrained regions of the stimulus space. We hypothesized that implicit-procedural category learning-allied to associative learning-would transfer weakly because it is yoked to the training stimuli. This result was confirmed for humans and monkeys. We hypothesized that explicit category learning-allied to abstract category rules-would transfer robustly. This result was confirmed only for humans. That is, humans displayed explicit category knowledge that transferred flawlessly. Monkeys did not. This result illuminates the distinctive abstractness, stimulus independence, and representational portability of humans' explicit category rules. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Measuring Explicit Word Learning of Preschool Children: A Development Study.

PubMed

Kelley, Elizabeth Spencer

2017-08-15

The purpose of this article is to present preliminary results related to the development of a new measure of explicit word learning. The measure incorporated elements of explicit vocabulary instruction and dynamic assessment and was designed to be sensitive to differences in word learning skill and to be feasible for use in clinical settings. The explicit word learning measure included brief teaching trials and repeated fine-grained measurement of semantic knowledge and production of 3 novel words (2 verbs and 1 adjective). Preschool children (N = 23) completed the measure of explicit word learning; standardized, norm-referenced measures of expressive and receptive vocabulary; and an incidental word learning task. The measure of explicit word learning provided meaningful information about word learning. Performance on the explicit measure was related to existing vocabulary knowledge and incidental word learning. Findings from this development study indicate that further examination of the measure of explicit word learning is warranted. The measure may have the potential to identify children who are poor word learners. https://doi.org/10.23641/asha.5170738.

Implicit measures of the stereotype content associated with disability.

PubMed

Rohmer, Odile; Louvet, Eva

2012-12-01

The present research aimed to show that the mixed stereotype content of persons with disability observed at an explicit level does not manifest itself using implicit measures. Two experimental studies were conducted to analyse the stereotype content of persons with a disability at the implicit level. The procedure used in this study was the concept priming paradigm. Furthermore, Study 2 also included an explicit measure. Results show important discrepancies between implicit and explicit measures. At an explicit level, previous work supporting the mixed stereotype content of persons with disability was replicated: participants judged these persons as warmer but less competent than persons without a disability. At an implicit level, a quite different pattern of results emerged: persons with a disability were associated not only with less competence than persons without disability, but also with less warmth. These findings suggest that the mixed pattern between warmth and competence generally observed at an explicit level may be based on societal pressures against prejudice and discrimination. ©2012 The British Psychological Society.

Narcissistic Traits and Explicit Self-Esteem: The Moderating Role of Implicit Self-View

PubMed Central

Di Pierro, Rossella; Mattavelli, Simone; Gallucci, Marcello

2016-01-01

Objective: Whilst the relationship between narcissism and self-esteem has been studied for a long time, findings are still controversial. The majority of studies investigated narcissistic grandiosity (NG), neglecting the existence of vulnerable manifestations of narcissism. Moreover, recent studies have shown that grandiosity traits are not always associated with inflated explicit self-esteem. The aim of the present study is to investigate the relationship between narcissistic traits and explicit self-esteem, distinguishing between grandiosity and vulnerability. Moreover, we consider the role of implicit self-esteem in qualifying these associations. Method: Narcissistic traits, explicit and implicit self-esteem measures were assessed among 120 university students (55.8% women, Mage = 22.55, SD = 3.03). Results: Results showed different patterns of association between narcissistic traits and explicit self-esteem, depending on phenotypic manifestations of narcissism. Narcissistic vulnerability (NV) was linked to low explicit self-evaluations regardless of one’s levels of implicit self-esteem. On the other hand, the link between NG and explicit self-esteem was qualified by levels of implicit self-views, such that grandiosity was significantly associated with inflated explicit self-evaluations only at either high or medium levels of implicit self-views. Discussion: These findings showed that the relationship between narcissistic traits and explicit self-esteem is not univocal, highlighting the importance of distinguishing between NG and NV. Finally, the study suggested that both researchers and clinicians should consider the relevant role of implicit self-views in conditioning self-esteem levels reported explicitly by individuals with grandiose narcissistic traits. PMID:27920739

Narcissistic Traits and Explicit Self-Esteem: The Moderating Role of Implicit Self-View.

PubMed

Di Pierro, Rossella; Mattavelli, Simone; Gallucci, Marcello

2016-01-01

Objective: Whilst the relationship between narcissism and self-esteem has been studied for a long time, findings are still controversial. The majority of studies investigated narcissistic grandiosity (NG), neglecting the existence of vulnerable manifestations of narcissism. Moreover, recent studies have shown that grandiosity traits are not always associated with inflated explicit self-esteem. The aim of the present study is to investigate the relationship between narcissistic traits and explicit self-esteem, distinguishing between grandiosity and vulnerability. Moreover, we consider the role of implicit self-esteem in qualifying these associations. Method: Narcissistic traits, explicit and implicit self-esteem measures were assessed among 120 university students (55.8% women, M age = 22.55, SD = 3.03). Results: Results showed different patterns of association between narcissistic traits and explicit self-esteem, depending on phenotypic manifestations of narcissism. Narcissistic vulnerability (NV) was linked to low explicit self-evaluations regardless of one's levels of implicit self-esteem. On the other hand, the link between NG and explicit self-esteem was qualified by levels of implicit self-views, such that grandiosity was significantly associated with inflated explicit self-evaluations only at either high or medium levels of implicit self-views. Discussion: These findings showed that the relationship between narcissistic traits and explicit self-esteem is not univocal, highlighting the importance of distinguishing between NG and NV. Finally, the study suggested that both researchers and clinicians should consider the relevant role of implicit self-views in conditioning self-esteem levels reported explicitly by individuals with grandiose narcissistic traits.

Explicit formulation of an anisotropic Allman/DKT 3-node thin triangular flat shell elements

NASA Astrophysics Data System (ADS)

Ertas, A.; Krafcik, J. T.; Ekwaro-Osire, S.

A simple, explicit formulation of the stiffness matrix for an anisotropic, 3-node, thin triangular, flat shell element in global coordinates is presented. An Allman triangle is used for membrane stiffness. The membrane stiffness matrix is explicitly derived by applying an Allman transformation to a Felippa 6-node linear strain triangle (LST). Bending stiffness is incorporated by the use of a discrete Kirchhoff triangle (DKT) bending triangle. Stiffness terms resulting from anisotropic membrane-bending coupling are included by integrating, in area coordinates, membrane and bending strain-displacement matrices.

Explicit finite-difference simulation of optical integrated devices on massive parallel computers.

PubMed

Sterkenburgh, T; Michels, R M; Dress, P; Franke, H

1997-02-20

An explicit method for the numerical simulation of optical integrated circuits by means of the finite-difference time-domain (FDTD) method is presented. This method, based on an explicit solution of Maxwell's equations, is well established in microwave technology. Although the simulation areas are small, we verified the behavior of three interesting problems, especially nonparaxial problems, with typical aspects of integrated optical devices. Because numerical losses are within acceptable limits, we suggest the use of the FDTD method to achieve promising quantitative simulation results.

Categorization and Prediction of Crimes of Passion Based on Attitudes Toward Violence.

PubMed

Guan, Muzhen; Li, Xiaojing; Xiao, Wei; Miao, Danmin; Liu, Xufeng

2017-11-01

The present study explored implicit and explicit attitudes toward violence in crimes of passion. Criminals ( n = 96) who had perpetrated crimes of passion and students ( n = 100) participated in this study. Explicit attitudes toward violence were evaluated using the Abnormal Personality Risk Inventory (APRI), and implicit attitude toward violence was evaluated using the Implicit Association Test (IAT). Results indicated that APRI scores of the perpetrators were significantly higher than that of the control group ( p < .05), suggesting that explicit attitudes toward violence could discriminate between the criminals and the control group. There was a significant IAT effect demonstrating a negative implicit attitude toward violence in both the control group and in the criminals ( n = 68); whereas there was a significant IAT effect manifesting a positive implicit attitude toward violence in the criminals ( n = 16) only. These results suggest that combining explicit and implicit attitudes could provide an empirical classification of crimes of passion.

Analytical validation of an explicit finite element model of a rolling element bearing with a localised line spall

NASA Astrophysics Data System (ADS)

Singh, Sarabjeet; Howard, Carl Q.; Hansen, Colin H.; Köpke, Uwe G.

2018-03-01

In this paper, numerically modelled vibration response of a rolling element bearing with a localised outer raceway line spall is presented. The results were obtained from a finite element (FE) model of the defective bearing solved using an explicit dynamics FE software package, LS-DYNA. Time domain vibration signals of the bearing obtained directly from the FE modelling were processed further to estimate time-frequency and frequency domain results, such as spectrogram and power spectrum, using standard signal processing techniques pertinent to the vibration-based monitoring of rolling element bearings. A logical approach to analyses of the numerically modelled results was developed with an aim to presenting the analytical validation of the modelled results. While the time and frequency domain analyses of the results show that the FE model generates accurate bearing kinematics and defect frequencies, the time-frequency analysis highlights the simulation of distinct low- and high-frequency characteristic vibration signals associated with the unloading and reloading of the rolling elements as they move in and out of the defect, respectively. Favourable agreement of the numerical and analytical results demonstrates the validation of the results from the explicit FE modelling of the bearing.

The time course of explicit and implicit categorization.

PubMed

Smith, J David; Zakrzewski, Alexandria C; Herberger, Eric R; Boomer, Joseph; Roeder, Jessica L; Ashby, F Gregory; Church, Barbara A

2015-10-01

Contemporary theory in cognitive neuroscience distinguishes, among the processes and utilities that serve categorization, explicit and implicit systems of category learning that learn, respectively, category rules by active hypothesis testing or adaptive behaviors by association and reinforcement. Little is known about the time course of categorization within these systems. Accordingly, the present experiments contrasted tasks that fostered explicit categorization (because they had a one-dimensional, rule-based solution) or implicit categorization (because they had a two-dimensional, information-integration solution). In Experiment 1, participants learned categories under unspeeded or speeded conditions. In Experiment 2, they applied previously trained category knowledge under unspeeded or speeded conditions. Speeded conditions selectively impaired implicit category learning and implicit mature categorization. These results illuminate the processing dynamics of explicit/implicit categorization.

The Impact of Textual Input Enhancement and Explicit Rule Presentation on Iranian Elementary EFL Learners' Intake of Simple Past Tense

ERIC Educational Resources Information Center

Nahavandi, Naemeh; Mukundan, Jayakaran

2013-01-01

The present study investigated the impact of textual input enhancement and explicit rule presentation on 93 Iranian EFL learners' intake of simple past tense. Three intact general English classes in Tabriz Azad University were randomly assigned to: 1) a control group; 2) a TIE group; and 3) a TIE plus explicit rule presentation group. All…

The Effect of Explicit vs. Implicit Instruction on the Learnability of English Consonant Clusters by Iranian Learners of English

ERIC Educational Resources Information Center

Khanbeiki, Ruhollah; Abdolmanafi-Rokni, Seyed Jalal

2015-01-01

The present study was aimed at providing the English teachers across Iran with a good and fruitful method of teaching pronunciation. To this end, sixty female intermediate EFL learners were put in three different but equivalent groups of 20 based on the results of a pronunciation pre-test. One of the groups received explicit instruction including…

Construction of non-Abelian gauge theories on noncommutative spaces

NASA Astrophysics Data System (ADS)

Jurčo, B.; Möller, L.; Schraml, S.; Schupp, P.; Wess, J.

We present a formalism to explicitly construct non-Abelian gauge theories on noncommutative spaces (induced via a star product with a constant Poisson tensor) from a consistency relation. This results in an expansion of the gauge parameter, the noncommutative gauge potential and fields in the fundamental representation, in powers of a parameter of the noncommutativity. This allows the explicit construction of actions for these gauge theories.

Children's and adults' use of verbal information to visually anticipate others' actions: A study on explicit and implicit social-cognitive processing.

PubMed

Paulus, Markus; Schuwerk, Tobias; Sodian, Beate; Ganglmayer, Kerstin

2017-03-01

According to recent theories, social cognition is based on two different types of information-processing; an implicit or action-based one and an explicit or verbal one. The present study examined whether implicit and explicit social-cognitive information processing interact with each other by investigating young children's and adults' use of verbal (i.e., explicit) information to predict others' actions. Employing eye-tracking to measure anticipatory eye-movements as a measure of implicit processing, Experiment 1 presented 1.5-, 2.5-, and 3.5-year-old children as well as adults with agents who announced to move to either of two possible targets. The results show that only the 3.5-year-old children and adults, but not the 1.5- and 2.5-year-old children were able to use verbal information to correctly anticipate others' actions. Yet, Experiments 2 and 3 showed that 2.5-year-old children were able to use explicit information to give a correct explicit answer (Experiment 2) and that they were able to use statistical information to anticipate the other's actions (Experiment 3). Overall, the study is in line with theoretical claims that two types of information-processing underlie human social cognition. It shows that these two inform each other by 3years of age. Copyright © 2016 Elsevier B.V. All rights reserved.

The Time Course of Explicit and Implicit Categorization

PubMed Central

Zakrzewski, Alexandria C.; Herberger, Eric; Boomer, Joseph; Roeder, Jessica; Ashby, F. Gregory; Church, Barbara A.

2015-01-01

Contemporary theory in cognitive neuroscience distinguishes, among the processes and utilities that serve categorization, explicit and implicit systems of category learning that learn, respectively, category rules by active hypothesis testing or adaptive behaviors by association and reinforcement. Little is known about the time course of categorization within these systems. Accordingly, the present experiments contrasted tasks that fostered explicit categorization (because they had a one-dimensional, rule-based solution) or implicit categorization (because they had a two-dimensional, information-integration solution). In Experiment 1, participants learned categories under unspeeded or speeded conditions. In Experiment 2, they applied previously trained category knowledge under unspeeded or speeded conditions. Speeded conditions selectively impaired implicit category learning and implicit mature categorization. These results illuminate the processing dynamics of explicit/implicit categorization. PMID:26025556

Implicit and explicit motor learning: Application to children with Autism Spectrum Disorder (ASD).

PubMed

Izadi-Najafabadi, Sara; Mirzakhani-Araghi, Navid; Miri-Lavasani, Negar; Nejati, Vahid; Pashazadeh-Azari, Zahra

2015-12-01

This study aims to determine whether children with Autism Spectrum Disorder (ASD) are capable of learning a motor skill both implicitly and explicitly. In the present study, 30 boys with ASD, aged 7-11 with IQ average of 81.2, were compared with 32 typical IQ- and age-matched boys on their performance on a serial reaction time task (SRTT). Children were grouped by ASD and typical children and by implicit and explicit learning groups for the SRTT. Implicit motor learning occurred in both children with ASD (p=.02) and typical children (p=.01). There were no significant differences between groups (p=.39). However, explicit motor learning was only observed in typical children (p=.01) not children with ASD (p=.40). There was a significant difference between groups for explicit learning (p=.01). The results of our study showed that implicit motor learning is not affected in children with ASD. Implications for implicit and explicit learning are applied to the CO-OP approach of motor learning with children with ASD. Copyright © 2015 Elsevier Ltd. All rights reserved.

Transient analysis of a thermal storage unit involving a phase change material

NASA Technical Reports Server (NTRS)

Griggs, E. I.; Pitts, D. R.; Humphries, W. R.

1974-01-01

The transient response of a single cell of a typical phase change material type thermal capacitor has been modeled using numerical conductive heat transfer techniques. The cell consists of a base plate, an insulated top, and two vertical walls (fins) forming a two-dimensional cavity filled with a phase change material. Both explicit and implicit numerical formulations are outlined. A mixed explicit-implicit scheme which treats the fin implicity while treating the phase change material explicitly is discussed. A band algorithmic scheme is used to reduce computer storage requirements for the implicit approach while retaining a relatively fine grid. All formulations are presented in dimensionless form thereby enabling application to geometrically similar problems. Typical parametric results are graphically presented for the case of melting with constant heat input to the base of the cell.

Flexible explicit but rigid implicit learning in a visuomotor adaptation task

PubMed Central

Bond, Krista M.

2015-01-01

There is mounting evidence for the idea that performance in a visuomotor rotation task can be supported by both implicit and explicit forms of learning. The implicit component of learning has been well characterized in previous experiments and is thought to arise from the adaptation of an internal model driven by sensorimotor prediction errors. However, the role of explicit learning is less clear, and previous investigations aimed at characterizing the explicit component have relied on indirect measures such as dual-task manipulations, posttests, and descriptive computational models. To address this problem, we developed a new method for directly assaying explicit learning by having participants verbally report their intended aiming direction on each trial. While our previous research employing this method has demonstrated the possibility of measuring explicit learning over the course of training, it was only tested over a limited scope of manipulations common to visuomotor rotation tasks. In the present study, we sought to better characterize explicit and implicit learning over a wider range of task conditions. We tested how explicit and implicit learning change as a function of the specific visual landmarks used to probe explicit learning, the number of training targets, and the size of the rotation. We found that explicit learning was remarkably flexible, responding appropriately to task demands. In contrast, implicit learning was strikingly rigid, with each task condition producing a similar degree of implicit learning. These results suggest that explicit learning is a fundamental component of motor learning and has been overlooked or conflated in previous visuomotor tasks. PMID:25855690

Gender Differences in Liking and Wanting Sex: Examining the Role of Motivational Context and Implicit Versus Explicit Processing.

PubMed

Dewitte, Marieke

2015-08-01

The present study investigated the specificity of sexual appraisal processes by making a distinction between implicit and explicit appraisals and between the affective (liking) and motivational (wanting) valence of sexual stimuli. These appraisals are assumed to diverge between men and women, depending on the context in which the sexual stimulus is encountered. Using an Implicit Association Test, explicit ratings, and film clips to prime a sexual, romantic or neutral motivational context, we investigated whether liking and wanting of sexual stimuli differed at the implicit and explicit level, differed between men and women, and were differentially sensitive to context manipulations. Results showed that, at the implicit level, women wanted more sex after being primed with romantic mood whereas men showed the least wanting of sex in the romantic condition. At the explicit level, men reported greater liking and wanting of sex than women, independently of context. We also found that women's (self-reported) sexual behavior was best predicted by the incentive salience of sexual stimuli whereas men's sexual behavior was more closely related to the hedonic qualities of sexual stimuli. Results were discussed in relation to an emotion-motivational account of sexual functioning.

Inattentional blindness for ignored words: comparison of explicit and implicit memory tasks.

PubMed

Butler, Beverly C; Klein, Raymond

2009-09-01

Inattentional blindness is described as the failure to perceive a supra-threshold stimulus when attention is directed away from that stimulus. Based on performance on an explicit recognition memory test and concurrent functional imaging data Rees, Russell, Frith, and Driver [Rees, G., Russell, C., Frith, C. D., & Driver, J. (1999). Inattentional blindness versus inattentional amnesia for fixated but ignored words. Science, 286, 2504-2507] reported inattentional blindness for word stimuli that were fixated but ignored. The present study examined both explicit and implicit memory for fixated but ignored words using a selective-attention task in which overlapping picture/word stimuli were presented at fixation. No explicit awareness of the unattended words was apparent on a recognition memory test. Analysis of an implicit memory task, however, indicated that unattended words were perceived at a perceptual level. Thus, the selective-attention task did not result in perfect filtering as suggested by Rees et al. While there was no evidence of conscious perception, subjects were not blind to the implicit perceptual properties of fixated but ignored words.

Are we puppets on a string? Comparing the impact of contingency and validity on implicit and explicit evaluations.

PubMed

Peters, Kurt R; Gawronski, Bertram

2011-04-01

Research has demonstrated that implicit and explicit evaluations of the same object can diverge. Explanations of such dissociations frequently appeal to dual-process theories, such that implicit evaluations are assumed to reflect object-valence contingencies independent of their perceived validity, whereas explicit evaluations reflect the perceived validity of object-valence contingencies. Although there is evidence supporting these assumptions, it remains unclear if dissociations can arise in situations in which object-valence contingencies are judged to be true or false during the learning of these contingencies. Challenging dual-process accounts that propose a simultaneous operation of two parallel learning mechanisms, results from three experiments showed that the perceived validity of evaluative information about social targets qualified both explicit and implicit evaluations when validity information was available immediately after the encoding of the valence information; however, delaying the presentation of validity information reduced its qualifying impact for implicit, but not explicit, evaluations.

The influence of vertical motor responses on explicit and incidental processing of power words.

PubMed

Jiang, Tianjiao; Sun, Lining; Zhu, Lei

2015-07-01

There is increasing evidence demonstrating that power judgment is affected by vertical information. Such interaction between vertical space and power (i.e., response facilitation under space-power congruent conditions) is generally elicited in paradigms that require participants to explicitly evaluate the power of the presented words. The current research explored the possibility that explicit evaluative processing is not a prerequisite for the emergence of this effect. Here we compared the influence of vertical information on a standard explicit power evaluation task with influence on a task that linked power with stimuli in a more incidental manner, requiring participants to report whether the words represented people or animals or the font of the words. The results revealed that although the effect is more modest, the interaction between responses and power is also evident in an incidental task. Furthermore, we also found that explicit semantic processing is a prerequisite to ensure such an effect. Copyright © 2015 Elsevier Inc. All rights reserved.

Implicit motives, explicit traits, and task and contextual performance at work.

PubMed

Lang, Jonas W B; Zettler, Ingo; Ewen, Christian; Hülsheger, Ute R

2012-11-01

Personality psychologists have long argued that explicit traits (as measured by questionnaires) channel the expression of implicit motives (as measured by coding imaginative verbal behavior) such that both interact in the prediction of relevant life outcome variables. In the present research, we apply these ideas in the context of industrial and organizational psychology and propose that 2 explicit traits work as channels for the expression of 3 core implicit motives in task and contextual job performance (extraversion for implicit affiliation and implicit power; explicit achievement for implicit achievement). As a test of these theoretical ideas, we report a study in which employees (N = 241) filled out a questionnaire booklet and worked on an improved modern implicit motive measure, the operant motive test. Their supervisors rated their task and contextual performance. Results support 4 of the 6 theoretical predictions and show that interactions between implicit motives and explicit traits increase the explained criterion variance in both task and contextual performance. (c) 2012 APA, all rights reserved.

Implicit and explicit false belief development in preschool children.

PubMed

Grosse Wiesmann, Charlotte; Friederici, Angela D; Singer, Tania; Steinbeis, Nikolaus

2017-09-01

The ability to represent the mental states of other agents is referred to as Theory of Mind (ToM). A developmental breakthrough in ToM consists of understanding that others can have false beliefs about the world. Recently, infants younger than 2 years of age have been shown to pass novel implicit false belief tasks. However, the processes underlying these tasks and their relation to later-developing explicit false belief understanding, as well as to other cognitive abilities, are not yet understood. Here, we study a battery of implicit and explicit false belief tasks in 3- and 4-year-old children, relating their performance to linguistic abilities and executive functions. The present data show a significant developmental change from failing explicit false belief tasks at 3 years of age to passing them at the age of 4, while both age groups pass implicit false belief tasks. This differential developmental trajectory is reflected by the finding that explicit and implicit false belief tasks do not correlate. Further, we demonstrate that explicit false belief tasks correlate with syntactic and executive functions, whereas implicit false belief tasks do not. The study thus indicates that the processes underlying implicit false belief tasks are different from later-developing explicit false belief understanding. Moreover, our results speak for a critical role of syntactic and executive functions for passing standard explicit false belief tasks in contrast to implicit tasks. © 2016 John Wiley & Sons Ltd.

Self-body recognition depends on implicit and explicit self-esteem.

PubMed

Richetin, Juliette; Xaiz, Annalisa; Maravita, Angelo; Perugini, Marco

2012-03-01

The present contribution bridges research on body image, self-esteem, and body recognition. Recent work in neuroscience indicates a superiority in the processing of self relative to others' body parts. The present contribution shows that this ability is not universal but it is qualified by individual differences in implicit and explicit self-esteem. In fact, two studies (n₁ = 41 and n₂ = 35) using two different paradigms in body recognition and direct and indirect measures of self-esteem reveal that this advantage in recognizing one's own body parts is associated with one's level of self-esteem. Moreover, it appears that measures of implicit and explicit self-esteem provide different contributions to self-body recognition abilities and that these contributions depend on how self-body recognition is assessed. Implications of these results are discussed notably in the perspective of research on body image. Copyright © 2011 Elsevier Ltd. All rights reserved.

How to calculate H3 better.

PubMed

Pavanello, Michele; Tung, Wei-Cheng; Adamowicz, Ludwik

2009-11-14

Efficient optimization of the basis set is key to achieving a very high accuracy in variational calculations of molecular systems employing basis functions that are explicitly dependent on the interelectron distances. In this work we present a method for a systematic enlargement of basis sets of explicitly correlated functions based on the iterative-complement-interaction approach developed by Nakatsuji [Phys. Rev. Lett. 93, 030403 (2004)]. We illustrate the performance of the method in the variational calculations of H(3) where we use explicitly correlated Gaussian functions with shifted centers. The total variational energy (-1.674 547 421 Hartree) and the binding energy (-15.74 cm(-1)) obtained in the calculation with 1000 Gaussians are the most accurate results to date.

Implicit but not explicit self-esteem predicts future depressive symptomatology.

PubMed

Franck, Erik; De Raedt, Rudi; De Houwer, Jan

2007-10-01

To date, research on the predictive validity of implicit self-esteem for depressive relapse is very sparse. In the present study, we assessed implicit self-esteem using the Name Letter Preference Task and explicit self-esteem using the Rosenberg self-esteem scale in a group of currently depressed patients, formerly depressed individuals, and never depressed controls. In addition, we examined the predictive validity of explicit, implicit, and the interaction of explicit and implicit self-esteem in predicting future symptoms of depression in formerly depressed individuals and never depressed controls. The results showed that currently depressed individuals reported a lower explicit self-esteem as compared to formerly depressed individuals and never depressed controls. In line with previous research, all groups showed a positive implicit self-esteem not different from each other. Furthermore, after controlling for initial depressive symptomatology, implicit but not explicit self-esteem significantly predicted depressive symptoms at six months follow-up. Although implicit self-esteem assessed with the Name Letter Preference Test was not different between formerly depressed individuals and never depressed controls, the findings suggest it is an interesting variable in the study of vulnerability for depression relapse.

The effects of divided attention on auditory priming.

PubMed

Mulligan, Neil W; Duke, Marquinn; Cooper, Angela W

2007-09-01

Traditional theorizing stresses the importance of attentional state during encoding for later memory, based primarily on research with explicit memory. Recent research has begun to investigate the role of attention in implicit memory but has focused almost exclusively on priming in the visual modality. The present experiments examined the effect of divided attention on auditory implicit memory, using auditory perceptual identification, word-stem completion and word-fragment completion. Participants heard study words under full attention conditions or while simultaneously carrying out a distractor task (the divided attention condition). In Experiment 1, a distractor task with low response frequency failed to disrupt later auditory priming (but diminished explicit memory as assessed with auditory recognition). In Experiment 2, a distractor task with greater response frequency disrupted priming on all three of the auditory priming tasks as well as the explicit test. These results imply that although auditory priming is less reliant on attention than explicit memory, it is still greatly affected by at least some divided-attention manipulations. These results are consistent with research using visual priming tasks and have relevance for hypotheses regarding attention and auditory priming.

Startle modulation and explicit valence evaluations dissociate during backward fear conditioning.

PubMed

Luck, Camilla C; Lipp, Ottmar V

2017-05-01

Blink startle magnitude is linearly modulated by affect such that, relative to neutral stimuli, startle magnitude is inhibited during pleasant stimuli and potentiated during unpleasant stimuli. Andreatta, Mühlberger, Yarali, Gerber, and Pauli (2010), however, report a dissociation between startle modulation and explicit valence evaluations during backward conditioning, a procedure in which the unconditional stimulus precedes the conditional stimulus (CS). Relative to controls, startles elicited during the CS were inhibited, suggesting that the CS had acquired positive valence, but participants still evaluated the CS as unpleasant after the experiment. In Experiment 1, we aimed to replicate this dissociation using a trial-by-trial measure of CS valence to measure startle modulation and CS valence simultaneously during forward and backward differential fear conditioning. In Experiment 2, we examined whether early and late portions of the CS could acquire differential valence by presenting startle probes at early and late probe positions during the CS. In both experiments, the dissociation between startle modulation and explicit valence evaluations in backward conditioning replicated, with CS+ evaluated as less pleasant than CS-, but startles elicited during CS+ inhibited relative to CS-. In Experiment 2, we provide preliminary evidence that this inhibition was present early, but not late, during the CS+. The results replicate the dissociation between implicit and explicit CS valence reported by Andreatta et al. (2010) using a trial-by-trial measure of valence. We also provide preliminary evidence that this dissociation may occur because the implicit and explicit measures are recorded at different times during the CS presentation. © 2017 Society for Psychophysiological Research.

A new heterogeneous asynchronous explicit-implicit time integrator for nonsmooth dynamics

NASA Astrophysics Data System (ADS)

Fekak, Fatima-Ezzahra; Brun, Michael; Gravouil, Anthony; Depale, Bruno

2017-07-01

In computational structural dynamics, particularly in the presence of nonsmooth behavior, the choice of the time-step and the time integrator has a critical impact on the feasibility of the simulation. Furthermore, in some cases, as in the case of a bridge crane under seismic loading, multiple time-scales coexist in the same problem. In that case, the use of multi-time scale methods is suitable. Here, we propose a new explicit-implicit heterogeneous asynchronous time integrator (HATI) for nonsmooth transient dynamics with frictionless unilateral contacts and impacts. Furthermore, we present a new explicit time integrator for contact/impact problems where the contact constraints are enforced using a Lagrange multiplier method. In other words, the aim of this paper consists in using an explicit time integrator with a fine time scale in the contact area for reproducing high frequency phenomena, while an implicit time integrator is adopted in the other parts in order to reproduce much low frequency phenomena and to optimize the CPU time. In a first step, the explicit time integrator is tested on a one-dimensional example and compared to Moreau-Jean's event-capturing schemes. The explicit algorithm is found to be very accurate and the scheme has generally a higher order of convergence than Moreau-Jean's schemes and provides also an excellent energy behavior. Then, the two time scales explicit-implicit HATI is applied to the numerical example of a bridge crane under seismic loading. The results are validated in comparison to a fine scale full explicit computation. The energy dissipated in the implicit-explicit interface is well controlled and the computational time is lower than a full-explicit simulation.

Efficient self-consistent viscous-inviscid solutions for unsteady transonic flow

NASA Technical Reports Server (NTRS)

Howlett, J. T.

1985-01-01

An improved method is presented for coupling a boundary layer code with an unsteady inviscid transonic computer code in a quasi-steady fashion. At each fixed time step, the boundary layer and inviscid equations are successively solved until the process converges. An explicit coupling of the equations is described which greatly accelerates the convergence process. Computer times for converged viscous-inviscid solutions are about 1.8 times the comparable inviscid values. Comparison of the results obtained with experimental data on three airfoils are presented. These comparisons demonstrate that the explicitly coupled viscous-inviscid solutions can provide efficient predictions of pressure distributions and lift for unsteady two-dimensional transonic flows.

Efficient self-consistent viscous-inviscid solutions for unsteady transonic flow

NASA Technical Reports Server (NTRS)

Howlett, J. T.

1985-01-01

An improved method is presented for coupling a boundary layer code with an unsteady inviscid transonic computer code in a quasi-steady fashion. At each fixed time step, the boundary layer and inviscid equations are successively solved until the process converges. An explicit coupling of the equations is described which greatly accelerates the convergence process. Computer times for converged viscous-inviscid solutions are about 1.8 times the comparable inviscid values. Comparison of the results obtained with experimental data on three airfoils are presented. These comparisons demonstrate that the explicitly coupled viscous-inviscid solutions can provide efficient predictions of pressure distributions and lift for unsteady two-dimensional transonic flow.

Explicit instruction of rules interferes with visuomotor skill transfer.

PubMed

Tanaka, Kanji; Watanabe, Katsumi

2017-06-01

In the present study, we examined the effects of explicit knowledge, obtained through instruction or spontaneous detection, on the transfer of visuomotor sequence learning. In the learning session, participants learned a visuomotor sequence, via trial and error. In the transfer session, the order of the sequence was reversed from that of the learning session. Before the commencement of the transfer session, some participants received explicit instruction regarding the reversal rule (i.e., Instruction group), while the others did not receive any information and were sorted into either an Aware or Unaware group, as assessed by interview conducted after the transfer session. Participants in the Instruction and Aware groups performed with fewer errors than the Unaware group in the transfer session. The participants in the Instruction group showed slower speed than the Aware and Unaware groups in the transfer session, and the sluggishness likely persisted even in late learning. These results suggest that explicit knowledge reduces errors in visuomotor skill transfer, but may interfere with performance speed, particularly when explicit knowledge is provided, as opposed to being spontaneously discovered.

Explicit Content Caching at Mobile Edge Networks with Cross-Layer Sensing

PubMed Central

Chen, Lingyu; Su, Youxing; Luo, Wenbin; Hong, Xuemin; Shi, Jianghong

2018-01-01

The deployment density and computational power of small base stations (BSs) are expected to increase significantly in the next generation mobile communication networks. These BSs form the mobile edge network, which is a pervasive and distributed infrastructure that can empower a variety of edge/fog computing applications. This paper proposes a novel edge-computing application called explicit caching, which stores selective contents at BSs and exposes such contents to local users for interactive browsing and download. We formulate the explicit caching problem as a joint content recommendation, caching, and delivery problem, which aims to maximize the expected user quality-of-experience (QoE) with varying degrees of cross-layer sensing capability. Optimal and effective heuristic algorithms are presented to solve the problem. The theoretical performance bounds of the explicit caching system are derived in simplified scenarios. The impacts of cache storage space, BS backhaul capacity, cross-layer information, and user mobility on the system performance are simulated and discussed in realistic scenarios. Results suggest that, compared with conventional implicit caching schemes, explicit caching can better exploit the mobile edge network infrastructure for personalized content dissemination. PMID:29565313

Explicit Content Caching at Mobile Edge Networks with Cross-Layer Sensing.

PubMed

Chen, Lingyu; Su, Youxing; Luo, Wenbin; Hong, Xuemin; Shi, Jianghong

2018-03-22

The deployment density and computational power of small base stations (BSs) are expected to increase significantly in the next generation mobile communication networks. These BSs form the mobile edge network, which is a pervasive and distributed infrastructure that can empower a variety of edge/fog computing applications. This paper proposes a novel edge-computing application called explicit caching, which stores selective contents at BSs and exposes such contents to local users for interactive browsing and download. We formulate the explicit caching problem as a joint content recommendation, caching, and delivery problem, which aims to maximize the expected user quality-of-experience (QoE) with varying degrees of cross-layer sensing capability. Optimal and effective heuristic algorithms are presented to solve the problem. The theoretical performance bounds of the explicit caching system are derived in simplified scenarios. The impacts of cache storage space, BS backhaul capacity, cross-layer information, and user mobility on the system performance are simulated and discussed in realistic scenarios. Results suggest that, compared with conventional implicit caching schemes, explicit caching can better exploit the mobile edge network infrastructure for personalized content dissemination.

The effects of divided attention on implicit and explicit memory performance.

PubMed

Schmitter-Edgecombe, M

1996-03-01

This study explored the nature of the relationship between attention available at learning and subsequent implicit and explicit memory performance. One hundred neurologically normal subjects rated their liking of target words on a five-point scale. Half of the subjects completed the word-rating task in a full attention condition and the other half performed the task in a divided attention condition. Following administration of the word-rating task, all subjects completed five memory tests, three implicit (category association, tachistoscopic identification, and perceptual clarification) and two explicit (semantic-cued recall and graphemic-cued recall), each bearing on a different subset of the list of previously presented target words. The results revealed that subjects in the divided attention condition performed significantly more poorly than subjects in the full attention condition on the explicit memory measures. In contrast, there were no significant group differences in performance on the implicit memory measures. These findings suggest that the attention to an episode that is necessary to produce later explicit memory may differ from that necessary to produce unconscious influences. The relationship between implicit memory, neurologic injury and automatic processes is discussed.

The Effects of Eliciting Implicit versus Explicit Social Support among Youths Susceptible for Late-Onset Smoking

PubMed Central

Roberts, Megan E.; Bernstein, Michael H.; Colby, Suzanne M.

2016-01-01

Purpose Adolescents susceptible to late-onset smoking (becoming regular smokers at age 18 or later) are an understudied population. Social support is a promising target for intervention, but it is important to distinguish between implicit social support (reminders that one belongs to a network of valued others) and explicit social support (seeking and receiving advice and emotional solace). This study aimed to test the potential protective influence of implicit and explicit social support on reducing the risk of late-onset smoking. Methods Fifty-eight smoking-susceptible youths (aged 16–18, 45% African American, 55% non-Hispanic White) completed an experimental session that included a video-recording task designed to elicit thoughts about implicit, explicit, or no social support. Youths reported their behavioral willingness and intentions (BW and BI) to smoke immediately following the social support manipulation; a random sample of 39 youths reported again at a 3-week follow-up. Results Following the manipulation, BW and BI for cigarette smoking were significantly higher among youths assigned to the explicit-support condition, compared to those in the implicit-support or control conditions. At follow-up, BW and BI were highest in the explicit-support condition and lowest in the implicit-support condition, but the differences were not significant. Conclusions Overall, findings indicated that for teens susceptible for late-onset smoking, eliciting thoughts about implicit social support produces lower risk for cigarette initiation than does eliciting thoughts about explicit social support. The present results and the video task that yielded them are important to researchers and practitioners interested in reducing the likelihood of late-onset smoking. PMID:27322670

Experimental interstellar organic chemistry - Preliminary findings

NASA Technical Reports Server (NTRS)

Khare, B. N.; Sagan, C.

1973-01-01

Review of the results of some explicit experimental simulation of interstellar organic chemistry consisting in low-temperature high-vacuum UV irradiation of condensed simple gases known or suspected to be present in the interstellar medium. The results include the finding that acetonitrile may be present in the interstellar medium. The implication of this and other findings are discussed.

A new solution method for wheel/rail rolling contact.

PubMed

Yang, Jian; Song, Hua; Fu, Lihua; Wang, Meng; Li, Wei

2016-01-01

To solve the problem of wheel/rail rolling contact of nonlinear steady-state curving, a three-dimensional transient finite element (FE) model is developed by the explicit software ANSYS/LS-DYNA. To improve the solving speed and efficiency, an explicit-explicit order solution method is put forward based on analysis of the features of implicit and explicit algorithm. The solution method was first applied to calculate the pre-loading of wheel/rail rolling contact with explicit algorithm, and then the results became the initial conditions in solving the dynamic process of wheel/rail rolling contact with explicit algorithm as well. Simultaneously, the common implicit-explicit order solution method is used to solve the FE model. Results show that the explicit-explicit order solution method has faster operation speed and higher efficiency than the implicit-explicit order solution method while the solution accuracy is almost the same. Hence, the explicit-explicit order solution method is more suitable for the wheel/rail rolling contact model with large scale and high nonlinearity.

Two-point derivative dispersion relations

NASA Astrophysics Data System (ADS)

Ferreira, Erasmo; Sesma, Javier

2013-03-01

A new derivation is given for the representation, under certain conditions, of the integral dispersion relations of scattering theory through local forms. The resulting expressions have been obtained through an independent procedure to construct the real part and consist of new mathematical structures of double infinite summations of derivatives. In this new form the derivatives are calculated at the generic value of the energy E and separately at the reference point E = m that is the lower limit of the integration. This new form may be more interesting in certain circumstances and directly shows the origin of the difficulties in convergence that were present in the old truncated forms called standard-derivative dispersion relations (DDR). For all cases in which the reductions of the double to single sums were obtained in our previous work, leading to explicit demonstration of convergence, these new expressions are seen to be identical to the previous ones. We present, as a glossary, the most simplified explicit results for the DDR's in the cases of imaginary amplitudes of forms (E/m)λ[ln (E/m)]n that cover the cases of practical interest in particle physics phenomenology at high energies. We explicitly study the expressions for the cases with λ negative odd integers, that require identification of cancelation of singularities, and provide the corresponding final results.

Feedback-related brain activity predicts learning from feedback in multiple-choice testing.

PubMed

Ernst, Benjamin; Steinhauser, Marco

2012-06-01

Different event-related potentials (ERPs) have been shown to correlate with learning from feedback in decision-making tasks and with learning in explicit memory tasks. In the present study, we investigated which ERPs predict learning from corrective feedback in a multiple-choice test, which combines elements from both paradigms. Participants worked through sets of multiple-choice items of a Swahili-German vocabulary task. Whereas the initial presentation of an item required the participants to guess the answer, corrective feedback could be used to learn the correct response. Initial analyses revealed that corrective feedback elicited components related to reinforcement learning (FRN), as well as to explicit memory processing (P300) and attention (early frontal positivity). However, only the P300 and early frontal positivity were positively correlated with successful learning from corrective feedback, whereas the FRN was even larger when learning failed. These results suggest that learning from corrective feedback crucially relies on explicit memory processing and attentional orienting to corrective feedback, rather than on reinforcement learning.

Characterizing Aeroelastic Systems Using Eigenanalysis, Explicitly Retaining The Aerodynamic Degrees of Freedom

NASA Technical Reports Server (NTRS)

Heeg, Jennifer; Dowell, Earl H.

2001-01-01

Discrete time aeroelastic models with explicitly retained aerodynamic modes have been generated employing a time marching vortex lattice aerodynamic model. This paper presents analytical results from eigenanalysis of these models. The potential of these models to calculate the behavior of modes that represent damped system motion (noncritical modes) in addition to the simple harmonic modes is explored. A typical section with only structural freedom in pitch is examined. The eigenvalues are examined and compared to experimental data. Issues regarding the convergence of the solution with regard to refining the aerodynamic discretization are investigated. Eigenvector behavior is examined; the eigenvector associated with a particular eigenvalue can be viewed as the set of modal participation factors for that particular mode. For the present formulation of the equations of motion, the vorticity for each aerodynamic element appears explicitly as an element of each eigenvector in addition to the structural dynamic generalized coordinates. Thus, modal participation of the aerodynamic degrees of freedom can be assessed in M addition to participation of structural degrees of freedom.

Assessment of the GECKO-A Modeling Tool and Simplified 3D Model Parameterizations for SOA Formation

NASA Astrophysics Data System (ADS)

Aumont, B.; Hodzic, A.; La, S.; Camredon, M.; Lannuque, V.; Lee-Taylor, J. M.; Madronich, S.

2014-12-01

Explicit chemical mechanisms aim to embody the current knowledge of the transformations occurring in the atmosphere during the oxidation of organic matter. These explicit mechanisms are therefore useful tools to explore the fate of organic matter during its tropospheric oxidation and examine how these chemical processes shape the composition and properties of the gaseous and the condensed phases. Furthermore, explicit mechanisms provide powerful benchmarks to design and assess simplified parameterizations to be included 3D model. Nevertheless, the explicit mechanism describing the oxidation of hydrocarbons with backbones larger than few carbon atoms involves millions of secondary organic compounds, far exceeding the size of chemical mechanisms that can be written manually. Data processing tools can however be designed to overcome these difficulties and automatically generate consistent and comprehensive chemical mechanisms on a systematic basis. The Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A) has been developed for the automatic writing of explicit chemical schemes of organic species and their partitioning between the gas and condensed phases. GECKO-A can be viewed as an expert system that mimics the steps by which chemists might develop chemical schemes. GECKO-A generates chemical schemes according to a prescribed protocol assigning reaction pathways and kinetics data on the basis of experimental data and structure-activity relationships. In its current version, GECKO-A can generate the full atmospheric oxidation scheme for most linear, branched and cyclic precursors, including alkanes and alkenes up to C25. Assessments of the GECKO-A modeling tool based on chamber SOA observations will be presented. GECKO-A was recently used to design a parameterization for SOA formation based on a Volatility Basis Set (VBS) approach. First results will be presented.

Racial bias in pain perception and response: experimental examination of automatic and deliberate processes

PubMed Central

Mathur, Vani A.; Richeson, Jennifer A.; Paice, Judith A.; Muzyka, Michael; Chiao, Joan Y.

2014-01-01

Racial disparities in pain treatment pose a significant public health and scientific problem. Prior studies demonstrate clinicians and non-clinicians are less perceptive, and suggest less treatment for, the pain of African Americans, relative to European Americans. Here we investigate the effects of explicit/implicit patient race presentation, patient race, and perceiver race on pain perception and response. African American and European American participants rated pain perception, empathy, helping motivation, and treatment suggestion in response to vignettes about patients’ pain. Vignettes were accompanied by a rapid (implicit), or static (explicit) presentation of an African or European American patient’s face. Participants perceived and responded more to European American patients in the implicit prime condition, when the effect of patient race was below the level of conscious regulation. This effect was reversed when patient race was presented explicitly. Additionally, female participants perceived and responded more to the pain of all patients, relative to male participants, and in the implicit prime condition, African American participants were more perceptive and responsive than European Americans to the pain of all patients. Taken together, these results suggest that known disparities in pain treatment may be largely due to automatic (below the level of conscious regulation), rather than deliberate (subject to conscious regulation) biases. These biases were not associated with traditional implicit measures of racial attitudes, suggesting that biases in pain perception and response may be independent of general prejudice. Perspective Results suggest racial biases in pain perception and treatment are at least partially due to automatic processes. When the relevance of patient race is made explicit, however, biases are attenuated and even reversed. We also find preliminary evidence that African Americans may be more sensitive to the pain of others than European Americans. PMID:24462976

Implicit and explicit mechanisms of word learning in a narrative context: an event-related potential study.

PubMed

Batterink, Laura; Neville, Helen

2011-11-01

The vast majority of word meanings are learned simply by extracting them from context rather than by rote memorization or explicit instruction. Although this skill is remarkable, little is known about the brain mechanisms involved. In the present study, ERPs were recorded as participants read stories in which pseudowords were presented multiple times, embedded in consistent, meaningful contexts (referred to as meaning condition, M+) or inconsistent, meaningless contexts (M-). Word learning was then assessed implicitly using a lexical decision task and explicitly through recall and recognition tasks. Overall, during story reading, M- words elicited a larger N400 than M+ words, suggesting that participants were better able to semantically integrate M+ words than M- words throughout the story. In addition, M+ words whose meanings were subsequently correctly recognized and recalled elicited a more positive ERP in a later time window compared with M+ words whose meanings were incorrectly remembered, consistent with the idea that the late positive component is an index of encoding processes. In the lexical decision task, no behavioral or electrophysiological evidence for implicit priming was found for M+ words. In contrast, during the explicit recognition task, M+ words showed a robust N400 effect. The N400 effect was dependent upon recognition performance, such that only correctly recognized M+ words elicited an N400. This pattern of results provides evidence that the explicit representations of word meanings can develop rapidly, whereas implicit representations may require more extensive exposure or more time to emerge.

The effects of environmental context on recognition memory and claims of remembering.

PubMed

Hockley, William E

2008-11-01

Recognition memory for words was tested in same or different contexts using the remember/know response procedure. Context was manipulated by presenting words in different screen colors and locations and by presenting words against real-world photographs. Overall hit and false-alarm rates were higher for tests presented in an old context compared to a new context. This concordant effect was seen in both remember responses and estimates of familiarity. Similar results were found for rearranged pairings of old study contexts and targets, for study contexts that were unique or were repeated with different words, and for new picture contexts that were physically similar to old contexts. Similar results were also found when subjects focused attention on the study words, but a different pattern of results was obtained when subjects explicitly associated the study words with their picture context. The results show that subjective feelings of recollection play a role in the effects of environmental context but are likely based more on a sense of familiarity that is evoked by the context than on explicit associations between targets and their study context.

Separation of Variables and Superintegrability; The symmetry of solvable systems

NASA Astrophysics Data System (ADS)

Kalnins, Ernest G.; Kress, Jonathan M.; Miller, Willard, Jr.

2018-06-01

Separation of variables methods for solving partial differential equations are of immense theoretical and practical importance in mathematical physics. They are the most powerful tool known for obtaining explicit solutions of the partial differential equations of mathematical physics. The purpose of this book is to give an up-to-date presentation of the theory of separation of variables and its relation to superintegrability. Collating and presenting it in a unified, updated and a more accessible manner, the results scattered in the literature that the authors have prepared is an invaluable resource for mathematicians and mathematical physicists in particular, as well as science, engineering, geological and biological researchers interested in explicit solutions.

Matrix elements for type 1 unitary irreducible representations of the Lie superalgebra gl(m|n)

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

Gould, Mark D.; Isaac, Phillip S.; Werry, Jason L.

Using our recent results on eigenvalues of invariants associated to the Lie superalgebra gl(m|n), we use characteristic identities to derive explicit matrix element formulae for all gl(m|n) generators, particularly non-elementary generators, on finite dimensional type 1 unitary irreducible representations. We compare our results with existing works that deal with only subsets of the class of type 1 unitary representations, all of which only present explicit matrix elements for elementary generators. Our work therefore provides an important extension to existing methods, and thus highlights the strength of our techniques which exploit the characteristic identities.

The effect of articulatory suppression on implicit and explicit false memory in the DRM paradigm.

PubMed

Van Damme, Ilse; Menten, Jan; d'Ydewalle, Gery

2010-11-01

Several studies have shown that reliable implicit false memory can be obtained in the DRM paradigm. There has been considerable debate, however, about whether or not conscious activation of critical lures during study is a necessary condition for this. Recent findings have revealed that articulatory suppression prevents subsequent false priming in an anagram task (Lovden & Johansson, 2003). The present experiment sought to replicate and extend these findings to an implicit word stem completion task, and to additionally investigate the effect of articulatory suppression on explicit false memory. Results showed an inhibitory effect of articulatory suppression on veridical memory, as well as on implicit false memory, whereas the level of explicit false memory was heightened. This suggests that articulatory suppression did not merely eliminate conscious lure activation, but had a more general capacity-delimiting effect. The drop in veridical memory can be attributed to diminished encoding of item-specific information. Superficial encoding also limited the spreading of semantic activation during study, which inhibited later false priming. In addition, the lack of item-specific and phenomenological details caused impaired source monitoring at test, resulting in heightened explicit false memory.

The role of chronic physical exercise and selective attention at encoding on implicit and explicit memory.

PubMed

Padilla, Concepción; Mayas, Julia; Ballesteros, Soledad; Andrés, Pilar

2017-09-01

Despite the evidence revealing benefits of chronic cardiovascular exercise on executive functions, little research has been conducted on long-term memory. We aimed to investigate the effect of physical exercise on implicit and explicit memory when attention was modulated at encoding in two groups of active and sedentary participants. With this purpose, attention was manipulated in a similar way in the implicit and explicit memory tasks by presenting picture outlines of two familiar objects, one in blue and the other in green, and participants were asked to pay attention only to one of them. Implicit memory was assessed through conceptual priming and explicit memory through a free recall task followed by recognition. The results did not reveal significant differences between groups in conceptual priming or free recall. However, in recognition, while both groups had similar discrimination for attended stimuli, active participants showed lower discrimination between unattended and new stimuli. These results suggested that exercise may have effects on specific cognitive processes, that is, that active participants may suppress non-relevant information better than sedentary participants, making the discrimination between unattended and new items more difficult.

Implicit-Explicit Time Integration Methods for Non-hydrostatic Atmospheric Models

NASA Astrophysics Data System (ADS)

Gardner, D. J.; Guerra, J. E.; Hamon, F. P.; Reynolds, D. R.; Ullrich, P. A.; Woodward, C. S.

2016-12-01

The Accelerated Climate Modeling for Energy (ACME) project is developing a non-hydrostatic atmospheric dynamical core for high-resolution coupled climate simulations on Department of Energy leadership class supercomputers. An important factor in computational efficiency is avoiding the overly restrictive time step size limitations of fully explicit time integration methods due to the stiffest modes present in the model (acoustic waves). In this work we compare the accuracy and performance of different Implicit-Explicit (IMEX) splittings of the non-hydrostatic equations and various Additive Runge-Kutta (ARK) time integration methods. Results utilizing the Tempest non-hydrostatic atmospheric model and the ARKode package show that the choice of IMEX splitting and ARK scheme has a significant impact on the maximum stable time step size as well as solution quality. Horizontally Explicit Vertically Implicit (HEVI) approaches paired with certain ARK methods lead to greatly improved runtimes. With effective preconditioning IMEX splittings that incorporate some implicit horizontal dynamics can be competitive with HEVI results. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-699187

Sexual Priming, Gender Stereotyping, and Likelihood to Sexually Harass: Examining the Cognitive Effects of Playing a Sexually-Explicit Video Game.

PubMed

Yao, Mike Z; Mahood, Chad; Linz, Daniel

2010-01-01

The present study examines the short-term cognitive effects of playing a sexually explicit video game with female "objectification" content on male players. Seventy-four male students from a university in California, U.S. participated in a laboratory experiment. They were randomly assigned to play either a sexually-explicit game or one of two control games. Participants' cognitive accessibility to sexual and sexually objectifying thoughts was measured in a lexical decision task. A likelihood-to-sexually-harass scale was also administered. Results show that playing a video game with the theme of female "objectification" may prime thoughts related to sex, encourage men to view women as sex objects, and lead to self-reported tendencies to behave inappropriately towards women in social situations.

Virtual-pulse time integral methodology: A new explicit approach for computational dynamics - Theoretical developments for general nonlinear structural dynamics

NASA Technical Reports Server (NTRS)

Chen, Xiaoqin; Tamma, Kumar K.; Sha, Desong

1993-01-01

The present paper describes a new explicit virtual-pulse time integral methodology for nonlinear structural dynamics problems. The purpose of the paper is to provide the theoretical basis of the methodology and to demonstrate applicability of the proposed formulations to nonlinear dynamic structures. Different from the existing numerical methods such as direct time integrations or mode superposition techniques, the proposed methodology offers new perspectives and methodology of development, and possesses several unique and attractive computational characteristics. The methodology is tested and compared with the implicit Newmark method (trapezoidal rule) through a nonlinear softening and hardening spring dynamic models. The numerical results indicate that the proposed explicit virtual-pulse time integral methodology is an excellent alternative for solving general nonlinear dynamic problems.

Time-fractional Cahn-Allen and time-fractional Klein-Gordon equations: Lie symmetry analysis, explicit solutions and convergence analysis

NASA Astrophysics Data System (ADS)

Inc, Mustafa; Yusuf, Abdullahi; Isa Aliyu, Aliyu; Baleanu, Dumitru

2018-03-01

This research analyzes the symmetry analysis, explicit solutions and convergence analysis to the time fractional Cahn-Allen (CA) and time-fractional Klein-Gordon (KG) equations with Riemann-Liouville (RL) derivative. The time fractional CA and time fractional KG are reduced to respective nonlinear ordinary differential equation of fractional order. We solve the reduced fractional ODEs using an explicit power series method. The convergence analysis for the obtained explicit solutions are investigated. Some figures for the obtained explicit solutions are also presented.

Implicit and explicit self-esteem discrepancies in people with psychogenic nonepileptic seizures.

PubMed

Dimaro, Lian V; Roberts, Nicole A; Moghaddam, Nima G; Dawson, David L; Brown, Ian; Reuber, Markus

2015-05-01

Self-esteem (SE), or one's sense of competence and worth, is reduced in many mental and physical disorders. Low SE is associated with perceived stigma and disability and poor treatment outcomes. The present study examined implicit and explicit SE (automatic and deliberate views about the self) in people with epilepsy and people with psychogenic nonepileptic seizures (PNESs). Discrepancies between implicit SE and explicit SE have been found to correlate with psychological distress in disorders often associated with PNESs but are relatively unexplored in PNESs. We hypothesized that, compared with epilepsy, PNESs would be associated with lower self-reported SE and greater discrepancies between implicit SE and explicit SE. Thirty adults with PNESs, 25 adults with epilepsy, and 31 controls without a history of seizures were asked to complete the Rosenberg Self-esteem Scale as a measure of explicit SE and an Implicit Relational Assessment Procedure as a measure of implicit SE. The State-Trait Anxiety Inventory and Patient Health Questionnaire-15 (a somatic symptom inventory) were also administered. We found significant group differences in explicit (p<0.001) but not implicit SE. Patients with PNESs reported lower SE than the other groups. No group differences were found in implicit SE. Implicit-explicit SE discrepancies were larger in the group with PNESs than in the other groups (p<0.001). Higher frequency of PNESs (but not epileptic seizures) was associated with lower explicit SE (rs=-.83, p<0.01) and greater SE discrepancies (i.e., lower explicit relative to implicit SE; rs=.65, p<0.01). These relationships remained significant when controlling for anxiety and somatization. Patients with PNESs had lower explicit SE than those with epilepsy or healthy controls. In keeping with our expectations, there were greater discrepancies between implicit SE and explicit SE among patients with PNESs than in the other groups. Our results, including the strong relationship between PNES frequency, anxiety, and explicit-implicit SE discrepancies, support the interpretation that PNESs serve to reduce cognitive dissonance, perhaps protecting patients' implicit SE. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Differential effects of uncertainty on LPP responses to emotional events during explicit and implicit anticipation.

PubMed

Lin, Huiyan; Liang, Jiafeng; Jin, Hua; Zhao, Dongmei

2018-07-01

Previous studies have investigated whether uncertainty influences neural responses to emotional events. The findings of such studies, particularly with respect to event-related potentials (ERPs), have been controversial due to several factors, such as the stimuli that serve as cues and the emotional content of the events. However, it is still unknown whether the effects of uncertainty on ERP responses to emotional events are influenced by anticipation patterns (e.g., explicit or implicit anticipation). To address this issue, participants in the present study were presented with anticipatory cues and then emotional (negative and neutral) pictures. The cues either did or did not signify the emotional content of the upcoming picture. In the inter-stimulus intervals between cues and pictures, participants were asked to estimate the expected probability of the occurrence of a specific emotional category of the subsequent picture based on a scale in the explicit anticipation condition, while in the implicit condition, participants were asked to indicate, using a number on a scale, which color was different from the others. The results revealed that in the explicit condition, uncertainty increased late positive potential (LPP) responses, particularly for negative pictures, whereas LPP responses were larger for certain negative pictures than for uncertain negative pictures in the implicit condition. The findings in the present study suggest that the anticipation pattern influences the effects of uncertainty when evaluation of negative events. Copyright © 2018 Elsevier B.V. All rights reserved.

Explicitly solvable complex Chebyshev approximation problems related to sine polynomials

NASA Technical Reports Server (NTRS)

Freund, Roland

1989-01-01

Explicitly solvable real Chebyshev approximation problems on the unit interval are typically characterized by simple error curves. A similar principle is presented for complex approximation problems with error curves induced by sine polynomials. As an application, some new explicit formulae for complex best approximations are derived.

Moderators of the Relationship between Implicit and Explicit Evaluation

ERIC Educational Resources Information Center

Nosek, Brian A.

2005-01-01

Automatic and controlled modes of evaluation sometimes provide conflicting reports of the quality of social objects. This article presents evidence for 4 moderators of the relationship between automatic (implicit) and controlled (explicit) evaluations. Implicit and explicit preferences were measured for a variety of object pairs using a large…

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.…

Investigation the Relationship among Language Learning Strategies, English Self-Efficacy, and Explicit Strategy Instructions

ERIC Educational Resources Information Center

Yang, Pei-Ling; Wang, Ai-Ling

2015-01-01

The present study aims to investigate the relationship among EFL college learners' language learning strategies, English self-efficacy, and explicit strategy instruction from the perspectives of Social Cognitive Theory. Three constructs, namely language learning strategies, English learning self-efficacy, and explicit strategy instruction, were…

A Mechanism for Reducing Delay Discounting by Altering Temporal Attention

PubMed Central

Radu, Peter T; Yi, Richard; Bickel, Warren K; Gross, James J; McClure, Samuel M

2011-01-01

Rewards that are not immediately available are discounted compared to rewards that are immediately available. The more a person discounts a delayed reward, the more likely that person is to have a range of behavioral problems, including clinical disorders. This latter observation has motivated the search for interventions that reduce discounting. One surprisingly simple method to reduce discounting is an “explicit-zero” reframing that states default or null outcomes. Reframing a classical discounting choice as “something now but nothing later” versus “nothing now but more later” decreases discount rates. However, it is not clear how this “explicit-zero” framing intervention works. The present studies delineate and test two possible mechanisms to explain the phenomenon. One mechanism proposes that the explicit-zero framing creates the impression of an improving sequence, thereby enhancing the present value of the delayed reward. A second possible mechanism posits an increase in attention allocation to temporally distant reward representations. In four experiments, we distinguish between these two hypothesized mechanisms and conclude that the temporal attention hypothesis is superior for explaining our results. We propose a model of temporal attention whereby framing affects intertemporal preferences by modifying present bias. PMID:22084496

Memory loss versus memory distortion: the role of encoding and retrieval deficits in Korsakoff patients' false memories.

PubMed

Van Damme, Ilse; d'Ydewalle, Gery

2009-05-01

Recent studies with the Deese/Roediger-McDermott (DRM) paradigm have revealed that Korsakoff patients show reduced levels of false recognition and different patterns of false recall compared to controls. The present experiment examined whether this could be attributed to an encoding deficit, or rather to problems with explicitly retrieving thematic information at test. In a variation on the DRM paradigm, both patients and controls were presented with associative as well as categorised word lists, with the order of recall and recognition tests manipulated between-subjects. The results point to an important role for the automatic/controlled retrieval distinction: Korsakoff patients' false memory was only diminished compared to controls' when automatic or short-term memory processes could not be used to fulfil the task at hand. Hence, the patients' explicit retrieval deficit appears to be crucial in explaining past and present data. Results are discussed in terms of fuzzy-trace and activation-monitoring theories.

Dissociation of Neural Substrates of Response Inhibition to Negative Information between Implicit and Explicit Facial Go/Nogo Tasks: Evidence from an Electrophysiological Study

PubMed Central

Sun, Shiyue; Carretié, Luis; Zhang, Lei; Dong, Yi; Zhu, Chunyan; Luo, Yuejia; Wang, Kai

2014-01-01

Background Although ample evidence suggests that emotion and response inhibition are interrelated at the behavioral and neural levels, neural substrates of response inhibition to negative facial information remain unclear. Thus we used event-related potential (ERP) methods to explore the effects of explicit and implicit facial expression processing in response inhibition. Methods We used implicit (gender categorization) and explicit emotional Go/Nogo tasks (emotion categorization) in which neutral and sad faces were presented. Electrophysiological markers at the scalp and the voxel level were analyzed during the two tasks. Results We detected a task, emotion and trial type interaction effect in the Nogo-P3 stage. Larger Nogo-P3 amplitudes during sad conditions versus neutral conditions were detected with explicit tasks. However, the amplitude differences between the two conditions were not significant for implicit tasks. Source analyses on P3 component revealed that right inferior frontal junction (rIFJ) was involved during this stage. The current source density (CSD) of rIFJ was higher with sad conditions compared to neutral conditions for explicit tasks, rather than for implicit tasks. Conclusions The findings indicated that response inhibition was modulated by sad facial information at the action inhibition stage when facial expressions were processed explicitly rather than implicitly. The rIFJ may be a key brain region in emotion regulation. PMID:25330212

A neurocomputational theory of how explicit learning bootstraps early procedural learning.

PubMed

Paul, Erick J; Ashby, F Gregory

2013-01-01

It is widely accepted that human learning and memory is mediated by multiple memory systems that are each best suited to different requirements and demands. Within the domain of categorization, at least two systems are thought to facilitate learning: an explicit (declarative) system depending largely on the prefrontal cortex, and a procedural (non-declarative) system depending on the basal ganglia. Substantial evidence suggests that each system is optimally suited to learn particular categorization tasks. However, it remains unknown precisely how these systems interact to produce optimal learning and behavior. In order to investigate this issue, the present research evaluated the progression of learning through simulation of categorization tasks using COVIS, a well-known model of human category learning that includes both explicit and procedural learning systems. Specifically, the model's parameter space was thoroughly explored in procedurally learned categorization tasks across a variety of conditions and architectures to identify plausible interaction architectures. The simulation results support the hypothesis that one-way interaction between the systems occurs such that the explicit system "bootstraps" learning early on in the procedural system. Thus, the procedural system initially learns a suboptimal strategy employed by the explicit system and later refines its strategy. This bootstrapping could be from cortical-striatal projections that originate in premotor or motor regions of cortex, or possibly by the explicit system's control of motor responses through basal ganglia-mediated loops.

Development of the use of conversational cues to assess reality status

PubMed Central

Woolley, Jacqueline D.; Ma, Lili; Lopez-Mobilia, Gabriel

2011-01-01

In this study we assessed children’s ability to use information overheard in other people’s conversations to judge the reality status of a novel entity. Three- to 9-year-old children (N = 101) watched video clips in which two adults conversed casually about a novel being. Videos contained statements that either explicitly denied, explicitly affirmed, or implicitly acknowledged the entity’s existence. Results indicated that children of all ages used statements of denial to discount the reality status of the novel entity, but that this ability improved with age. By age 5, children used implicit existence cues to judge a novel entity as being real. Not until age 9, however, did children begin to doubt the existence of entities whose reality status was explicitly affirmed in conversation. Overall, results indicate that the ability to use conversational cues to determine reality status is present in some children as early as age 3, but recognition of the nuanced language of belief continues to develop during the elementary-school years. PMID:22241965

Toward real-time performance benchmarks for Ada

NASA Technical Reports Server (NTRS)

Clapp, Russell M.; Duchesneau, Louis; Volz, Richard A.; Mudge, Trevor N.; Schultze, Timothy

1986-01-01

The issue of real-time performance measurements for the Ada programming language through the use of benchmarks is addressed. First, the Ada notion of time is examined and a set of basic measurement techniques are developed. Then a set of Ada language features believed to be important for real-time performance are presented and specific measurement methods discussed. In addition, other important time related features which are not explicitly part of the language but are part of the run-time related features which are not explicitly part of the language but are part of the run-time system are also identified and measurement techniques developed. The measurement techniques are applied to the language and run-time system features and the results are presented.

Implicit and explicit mechanisms of word learning in a narrative context: an event-related potential study

PubMed Central

Batterink, Laura; Neville, Helen

2011-01-01

The vast majority of word meanings are learned simply by extracting them from context, rather than by rote memorization or explicit instruction. Although this skill is remarkable, little is known about the brain mechanisms involved. In the present study, ERPs were recorded as participants read stories in which pseudowords were presented multiple times, embedded in consistent, meaningful contexts (referred to as meaning condition, M+) or inconsistent, meaningless contexts (M−). Word learning was then assessed implicitly using a lexical decision task and explicitly through recall and recognition tasks. Overall, during story reading, M− words elicited a larger N400 than M+ words, suggesting that participants were better able to semantically integrate M+ words than M− words throughout the story. In addition, M+ words whose meanings were subsequently correctly recognized and recalled elicited a more positive ERP in a later time-window compared to M+ words whose meanings were incorrectly remembered, consistent with the idea that the late positive component (LPC) is an index of encoding processes. In the lexical decision task, no behavioral or electrophysiological evidence for implicit priming was found for M+ words. In contrast, during the explicit recognition task, M+ words showed a robust N400 effect. The N400 effect was dependent upon recognition performance, such that only correctly recognized M+ words elicited an N400. This pattern of results provides evidence that the explicit representations of word meanings can develop rapidly, while implicit representations may require more extensive exposure or more time to emerge. PMID:21452941

Three Dimensional Explicit Model for Cometary Tail Ions Interactions with Solar Wind

NASA Astrophysics Data System (ADS)

Al Bermani, M. J. F.; Alhamed, S. A.; Khalaf, S. Z.; Ali, H. Sh.; Selman, A. A.

2009-06-01

The different interactions between cometary tail and solar wind ions are studied in the present paper based on three-dimensional Lax explicit method. The model used in this research is based on the continuity equations describing the cometary tail-solar wind interactions. Three dimensional system was considered in this paper. Simulation of the physical system was achieved using computer code written using Matlab 7.0. The parameters studied here assumed Halley comet type and include the particle density rho, the particles velocity v, the magnetic field strength B, dynamic pressure p and internal energy E. The results of the present research showed that the interaction near the cometary nucleus is mainly affected by the new ions added to the plasma of the solar wind, which increases the average molecular weight and result in many unique characteristics of the cometary tail. These characteristics were explained in the presence of the IMF.

Exact Local Correlations and Full Counting Statistics for Arbitrary States of the One-Dimensional Interacting Bose Gas

NASA Astrophysics Data System (ADS)

Bastianello, Alvise; Piroli, Lorenzo; Calabrese, Pasquale

2018-05-01

We derive exact analytic expressions for the n -body local correlations in the one-dimensional Bose gas with contact repulsive interactions (Lieb-Liniger model) in the thermodynamic limit. Our results are valid for arbitrary states of the model, including ground and thermal states, stationary states after a quantum quench, and nonequilibrium steady states arising in transport settings. Calculations for these states are explicitly presented and physical consequences are critically discussed. We also show that the n -body local correlations are directly related to the full counting statistics for the particle-number fluctuations in a short interval, for which we provide an explicit analytic result.

Combined AIE/EBE/GMRES approach to incompressible flows. [Adaptive Implicit-Explicit/Grouped Element-by-Element/Generalized Minimum Residuals

NASA Technical Reports Server (NTRS)

Liou, J.; Tezduyar, T. E.

1990-01-01

Adaptive implicit-explicit (AIE), grouped element-by-element (GEBE), and generalized minimum residuals (GMRES) solution techniques for incompressible flows are combined. In this approach, the GEBE and GMRES iteration methods are employed to solve the equation systems resulting from the implicitly treated elements, and therefore no direct solution effort is involved. The benchmarking results demonstrate that this approach can substantially reduce the CPU time and memory requirements in large-scale flow problems. Although the description of the concepts and the numerical demonstration are based on the incompressible flows, the approach presented here is applicable to larger class of problems in computational mechanics.

Binding in pair potentials of liquid simple metals from nonlocality in electronic kinetic energy

NASA Technical Reports Server (NTRS)

Perrot, F.; March, N. H.

1990-01-01

The paper presents an explicit expression for the pair potential in liquid simple metals from low-order density-gradient theory when the superposition of single-center displaced charges is employed. Numerical results are presented for the gradient expansion pair interaction in liquid Na and Be. The low-order density-gradient equation for the pair potential is presented.

Resistance to Persuasion as a Consequence of Influence Attempts in Advertising and Non-Advertising Communications.

ERIC Educational Resources Information Center

Schwarz, Norbert; And Others

1986-01-01

College students read a communication about a textbook, designated either as a "review" or an "advertisement," and containing either a highly explicit or a less explicit influence attempt. Both presenting the communication as an advertisement and a highly explicit influence attempt reduced the communication's effectiveness, indicating the…

Enhancing Core Mathematics Instruction for Students at Risk for Mathematics Disabilities

ERIC Educational Resources Information Center

Doabler, Christian T.; Cary, Mari Strand; Jungjohann, Kathleen; Clarke, Ben; Fien, Hank; Baker, Scott; Smolkowski, Keith; Chard, David

2012-01-01

This paper presents eight practical guidelines that teachers can use to make core instruction more systematic and explicit for students with or at-risk for mathematics disabilities. In the paper, we use the notion of explicit and systematic instruction as a foundation for intensifying core math instruction. Explicit and systematic core instruction…

Intrusive effects of implicitly processed information on explicit memory.

PubMed

Sentz, Dustin F; Kirkhart, Matthew W; LoPresto, Charles; Sobelman, Steven

2002-02-01

This study described the interference of implicitly processed information on the memory for explicitly processed information. Participants studied a list of words either auditorily or visually under instructions to remember the words (explicit study). They were then visually presented another word list under instructions which facilitate implicit but not explicit processing. Following a distractor task, memory for the explicit study list was tested with either a visual or auditory recognition task that included new words, words from the explicit study list, and words implicitly processed. Analysis indicated participants both failed to recognize words from the explicit study list and falsely recognized words that were implicitly processed as originating from the explicit study list. However, this effect only occurred when the testing modality was visual, thereby matching the modality for the implicitly processed information, regardless of the modality of the explicit study list. This "modality effect" for explicit memory was interpreted as poor source memory for implicitly processed information and in light of the procedures used. as well as illustrating an example of "remembering causing forgetting."

Implicit and Explicit Contributions to Object Recognition: Evidence from Rapid Perceptual Learning

PubMed Central

Hassler, Uwe; Friese, Uwe; Gruber, Thomas

2012-01-01

The present study investigated implicit and explicit recognition processes of rapidly perceptually learned objects by means of steady-state visual evoked potentials (SSVEP). Participants were initially exposed to object pictures within an incidental learning task (living/non-living categorization). Subsequently, degraded versions of some of these learned pictures were presented together with degraded versions of unlearned pictures and participants had to judge, whether they recognized an object or not. During this test phase, stimuli were presented at 15 Hz eliciting an SSVEP at the same frequency. Source localizations of SSVEP effects revealed for implicit and explicit processes overlapping activations in orbito-frontal and temporal regions. Correlates of explicit object recognition were additionally found in the superior parietal lobe. These findings are discussed to reflect facilitation of object-specific processing areas within the temporal lobe by an orbito-frontal top-down signal as proposed by bi-directional accounts of object recognition. PMID:23056558

Financial incentives for a healthy life style and disease prevention among older people: a systematic literature review.

PubMed

Tambor, Marzena; Pavlova, Milena; Golinowska, Stanisława; Arsenijevic, Jelena; Groot, Wim

2016-09-05

To motivate people to lead a healthier life and to engage in disease prevention, explicit financial incentives, such as monetary rewards for attaining health-related targets (e.g. smoking cessation, weight loss or increased physical activity) or disincentives for reverting to unhealthy habits, are applied. A review focused on financial incentives for health promotion among older people is lacking. Attention to this group is necessary because older people may respond differently to financial incentives, e.g. because of differences in opportunity costs and health perceptions. To outline how explicit financial incentives for healthy lifestyle and disease prevention work among older persons, this study reviews the recent evidence on this topic. We applied the method of systematic literature review and we searched in PUBMED, ECONLIT and COCHRANE LIBRARY for studies focused on explicit financial incentives targeted at older adults to promote health and stimulate primary prevention as well as screening. The publications selected as relevant were analyzed based on directed (relational) content analysis. The results are presented in a narrative manner complemented with an appendix table that describes the study details. We assessed the design of the studies reported in the publications in a qualitative manner. We also checked the quality of our review using the PRISMA 2009 checklist. We identified 15 studies on the role of explicit financial incentives in changing health-related behavior of older people. They include both, quantitative studies on the effectiveness of financial rewards as well as qualitative studies on the acceptability of financial incentives. The quantitative studies are characterized by a great diversity of designs and provide mixed results on the effects of explicit financial incentives. The results of the qualitative studies indicate limited trust of older people in the use of explicit financial incentives for health promotion and prevention. More research is needed on the effects of explicit financial incentives for prevention and promotion among older people before their broader use can be recommended. Overall, the design of the financial incentive system may be a crucial element in their acceptability.

Lie symmetry analysis, explicit solutions and conservation laws for the space-time fractional nonlinear evolution equations

NASA Astrophysics Data System (ADS)

Inc, Mustafa; Yusuf, Abdullahi; Aliyu, Aliyu Isa; Baleanu, Dumitru

2018-04-01

This paper studies the symmetry analysis, explicit solutions, convergence analysis, and conservation laws (Cls) for two different space-time fractional nonlinear evolution equations with Riemann-Liouville (RL) derivative. The governing equations are reduced to nonlinear ordinary differential equation (ODE) of fractional order using their Lie point symmetries. In the reduced equations, the derivative is in Erdelyi-Kober (EK) sense, power series technique is applied to derive an explicit solutions for the reduced fractional ODEs. The convergence of the obtained power series solutions is also presented. Moreover, the new conservation theorem and the generalization of the Noether operators are developed to construct the nonlocal Cls for the equations . Some interesting figures for the obtained explicit solutions are presented.

Higher order explicit symmetric integrators for inseparable forms of coordinates and momenta

NASA Astrophysics Data System (ADS)

Liu, Lei; Wu, Xin; Huang, Guoqing; Liu, Fuyao

2016-06-01

Pihajoki proposed the extended phase-space second-order explicit symmetric leapfrog methods for inseparable Hamiltonian systems. On the basis of this work, we survey a critical problem on how to mix the variables in the extended phase space. Numerical tests show that sequent permutations of coordinates and momenta can make the leapfrog-like methods yield the most accurate results and the optimal long-term stabilized error behaviour. We also present a novel method to construct many fourth-order extended phase-space explicit symmetric integration schemes. Each scheme represents the symmetric production of six usual second-order leapfrogs without any permutations. This construction consists of four segments: the permuted coordinates, triple product of the usual second-order leapfrog without permutations, the permuted momenta and the triple product of the usual second-order leapfrog without permutations. Similarly, extended phase-space sixth, eighth and other higher order explicit symmetric algorithms are available. We used several inseparable Hamiltonian examples, such as the post-Newtonian approach of non-spinning compact binaries, to show that one of the proposed fourth-order methods is more efficient than the existing methods; examples include the fourth-order explicit symplectic integrators of Chin and the fourth-order explicit and implicit mixed symplectic integrators of Zhong et al. Given a moderate choice for the related mixing and projection maps, the extended phase-space explicit symplectic-like methods are well suited for various inseparable Hamiltonian problems. Samples of these problems involve the algorithmic regularization of gravitational systems with velocity-dependent perturbations in the Solar system and post-Newtonian Hamiltonian formulations of spinning compact objects.

"Like the palm of my hands": Motor imagery enhances implicit and explicit visual recognition of one's own hands.

PubMed

Conson, Massimiliano; Volpicella, Francesco; De Bellis, Francesco; Orefice, Agnese; Trojano, Luigi

2017-10-01

A key point in motor imagery literature is that judging hands in palm view recruits sensory-motor information to a higher extent than judging hands in back view, due to the greater biomechanical complexity implied in rotating hands depicted from palm than from back. We took advantage from this solid evidence to test the nature of a phenomenon known as self-advantage, i.e. the advantage in implicitly recognizing self vs. others' hand images. The self-advantage has been actually found when implicitly but not explicitly judging self-hands, likely due to dissociation between implicit and explicit body representations. However, such a finding might be related to the extent to which motor imagery is recruited during implicit and explicit processing of hand images. We tested this hypothesis in two behavioural experiments. In Experiment 1, right-handed participants judged laterality of either self or others' hands, whereas in Experiment 2, an explicit recognition of one's own hands was required. Crucially, in both experiments participants were randomly presented with hand images viewed from back or from palm. The main result of both experiments was the self-advantage when participants judged hands from palm view. This novel finding demonstrate that increasing the "motor imagery load" during processing of self vs. others' hands can elicit a self-advantage in explicit recognition tasks as well. Future studies testing the possible dissociation between implicit and explicit visual body representations should take into account the modulatory effect of motor imagery load on self-hand processing. Copyright © 2017. Published by Elsevier B.V.

Emotion effects on implicit and explicit musical memory in normal aging.

PubMed

Narme, Pauline; Peretz, Isabelle; Strub, Marie-Laure; Ergis, Anne-Marie

2016-12-01

Normal aging affects explicit memory while leaving implicit memory relatively spared. Normal aging also modifies how emotions are processed and experienced, with increasing evidence that older adults (OAs) focus more on positive information than younger adults (YAs). The aim of the present study was to investigate how age-related changes in emotion processing influence explicit and implicit memory. We used emotional melodies that differed in terms of valence (positive or negative) and arousal (high or low). Implicit memory was assessed with a preference task exploiting exposure effects, and explicit memory with a recognition task. Results indicated that effects of valence and arousal interacted to modulate both implicit and explicit memory in YAs. In OAs, recognition was poorer than in YAs; however, recognition of positive and high-arousal (happy) studied melodies was comparable. Insofar as socioemotional selectivity theory (SST) predicts a preservation of the recognition of positive information, our findings are not fully consistent with the extension of this theory to positive melodies since recognition of low-arousal (peaceful) studied melodies was poorer in OAs. In the preference task, YAs showed stronger exposure effects than OAs, suggesting an age-related decline of implicit memory. This impairment is smaller than the one observed for explicit memory (recognition), extending to the musical domain the dissociation between explicit memory decline and implicit memory relative preservation in aging. Finally, the disproportionate preference for positive material seen in OAs did not translate into stronger exposure effects for positive material suggesting no age-related emotional bias in implicit memory. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

A novel explicit equation for the friction factor prediction in the annular flow with drag-reducing polymer

NASA Astrophysics Data System (ADS)

Lakzian, Esmail; Masoudifar, Amir; Saghi, Hassan

2017-03-01

In this paper, a novel explicit equation is presented for the friction factor prediction in the annular flow with drag reducing polymer (DRP). By using dimensional analyses and curve fitting on the published experimental data, the suggested equation is derived based on the logarithmic velocity profiles and power law in boundary layers. In the next step, a least squares method is used to calibrate the presented equation. Then, the equation is used to friction factor prediction of the gas-liquid mixture with DRP and the results are compared with the experimental data and the Al-Sarkhi ones. Finally, drag reduction (DR) is applied as the ratio of the friction factor reduction using DRP to the friction factor without DRP. The DR results show that the suggested equation has a better agreement with the experimental data in comparison with the pervious equations. The results also show that DR prediction decreases with the increase of the gas superficial velocity.

From water use to water scarcity footprinting in environmentally extended input-output analysis.

PubMed

Ridoutt, Bradley George; Hadjikakou, Michalis; Nolan, Martin; Bryan, Brett A

2018-05-18

Environmentally extended input-output analysis (EEIOA) supports environmental policy by quantifying how demand for goods and services leads to resource use and emissions across the economy. However, some types of resource use and emissions require spatially-explicit impact assessment for meaningful interpretation, which is not possible in conventional EEIOA. For example, water use in locations of scarcity and abundance is not environmentally equivalent. Opportunities for spatially-explicit impact assessment in conventional EEIOA are limited because official input-output tables tend to be produced at the scale of political units which are not usually well aligned with environmentally relevant spatial units. In this study, spatially-explicit water scarcity factors and a spatially disaggregated Australian water use account were used to develop water scarcity extensions that were coupled with a multi-regional input-output model (MRIO). The results link demand for agricultural commodities to the problem of water scarcity in Australia and globally. Important differences were observed between the water use and water scarcity footprint results, as well as the relative importance of direct and indirect water use, with significant implications for sustainable production and consumption-related policies. The approach presented here is suggested as a feasible general approach for incorporating spatially-explicit impact assessment in EEIOA.

Investigation of High School Students' Online Science Information Searching Performance: The Role of Implicit and Explicit Strategies

NASA Astrophysics Data System (ADS)

Tsai, Meng-Jung; Hsu, Chung-Yuan; Tsai, Chin-Chung

2012-04-01

Due to a growing trend of exploring scientific knowledge on the Web, a number of studies have been conducted to highlight examination of students' online searching strategies. The investigation of online searching generally employs methods including a survey, interview, screen-capturing, or transactional logs. The present study firstly intended to utilize a survey, the Online Information Searching Strategies Inventory (OISSI), to examine users' searching strategies in terms of control, orientation, trial and error, problem solving, purposeful thinking, selecting main ideas, and evaluation, which is defined as implicit strategies. Second, this study conducted screen-capturing to investigate the students' searching behaviors regarding the number of keywords, the quantity and depth of Web page exploration, and time attributes, which is defined as explicit strategies. Ultimately, this study explored the role that these two types of strategies played in predicting the students' online science information searching outcomes. A total of 103 Grade 10 students were recruited from a high school in northern Taiwan. Through Pearson correlation and multiple regression analyses, the results showed that the students' explicit strategies, particularly the time attributes proposed in the present study, were more successful than their implicit strategies in predicting their outcomes of searching science information. The participants who spent more time on detailed reading (explicit strategies) and had better skills of evaluating Web information (implicit strategies) tended to have superior searching performance.

Explicit semantic tasks are necessary to study semantic priming effects with high rates of repetition.

PubMed

Renoult, Louis; Wang, Xiaoxiao; Mortimer, Jennifer; Debruille, J Bruno

2012-04-01

The purpose of the present study was to clarify in which experimental conditions the semantic processing of repeated words is preserved. We contrasted a short (250 ms) and a long (1000 ms) stimulus onset asynchrony (SOA) in two different experiments, using a relatively low proportion of related words (30%). One group of participants performed a lexical decision task (LDT) and a second group performed an explicit semantic matching task with the same words (except for pseudowords) and the same task parameters. In both tasks, word stimuli consisted solely of two prime and two target words repeated throughout the experiment. The effects of semantic priming on reaction time (RT) and the amplitude of the N400 ERP were absent for both the short and the long SOA in the LDT. In contrast, in the explicit semantic task, these effects were significant. In this task, the activity of N400 generators in the left superior temporal gyrus and the inferior parietal cortex significantly differentiated primed and unprimed trials but this effect did not interact with SOA. Our results indicate that task instruction is critical to preserve semantic processing with repeated presentations. Using explicit semantic designs, it may be possible to study associative or categorical relations between individual concepts. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

How Can Implicit and Explicit Attitudes Both Be Changed? Testing Two Interventions to Promote Consumption of Green Vegetables.

PubMed

Mattavelli, Simone; Avishai, Aya; Perugini, Marco; Richetin, Juliette; Sheeran, Paschal

2017-08-01

Although correlational studies have demonstrated that implicit and explicit attitudes are both important in predicting eating behavior, few studies targeting food choice have attempted to change both types of attitudes. We tested the impact of (a) an evaluative learning intervention that uses the self to change attitudes (i.e., a Self-Referencing task) and (b) a persuasive communication in modifying implicit and explicit attitudes towards green vegetables and promoting readiness to change. The study targeted individuals who explicitly reported they did not like or only moderately liked green vegetables. Participants (N = 273) were randomly allocated to a 2 (self-referencing: present vs. absent) × 2 (persuasive message: present vs. absent) factorial design. The outcomes were implicit and explicit attitudes as well as readiness to increase consumption of green vegetables. Implicit attitudes increased after repeatedly pairing green vegetable stimuli with the self in the self-referencing task but did not change in response to the persuasive communication. The persuasive message increased explicit attitudes and readiness to change, but did not alter implicit attitudes. A three-way interaction with pre-existing explicit attitudes was also observed. In the absence of a persuasive message, the self-referencing task increased on readiness to change among participants with more negative pre-existing explicit attitudes. This study is the first to demonstrate that a self-referencing task is effective in changing both implicit attitudes and readiness to change eating behavior. Findings indicate that distinct intervention strategies are needed to change implicit and explicit attitudes towards green vegetables.

Re-Evaluating Dissociations between Implicit and Explicit Category Learning: An Event-Related fMRI Study

ERIC Educational Resources Information Center

Gureckis, Todd M.; James, Thomas W.; Nosofsky, Robert M.

2011-01-01

Recent fMRI studies have found that distinct neural systems may mediate perceptual category learning under implicit and explicit learning conditions. In these previous studies, however, different stimulus-encoding processes may have been associated with implicit versus explicit learning. The present design was aimed at decoupling the influence of…

The Effectiveness of Using an Explicit Language Learning Strategy-Based Instruction in Developing Secondary School Students' EFL Listening Comprehension Skills

ERIC Educational Resources Information Center

Amin, Iman Abdul-Reheem; Amin, Magdy Mohammad; Aly, Mahsoub Abdul-Sadeq

2011-01-01

The present study aimed at exploring the effectiveness of using explicit language learning strategy-based instruction in developing secondary school students' EFL listening comprehension skills. It was hypothesized that using explicit strategy-based instruction would develop students' EFL listening comprehension skill and its sub-skills. The…

A masked negative self-esteem? Implicit and explicit self-esteem in patients with Narcissistic Personality Disorder.

PubMed

Marissen, Marlies A E; Brouwer, Marlies E; Hiemstra, Annemarie M F; Deen, Mathijs L; Franken, Ingmar H A

2016-08-30

The mask model of narcissism states that the narcissistic traits of patients with NPD are the result of a compensatory reaction to underlying ego fragility. This model assumes that high explicit self-esteem masks low implicit self-esteem. However, research on narcissism has predominantly focused on non-clinical participants and data derived from patients diagnosed with Narcissistic Personality Disorder (NPD) remain scarce. Therefore, the goal of the present study was to test the mask model hypothesis of narcissism among patients with NPD. Male patients with NPD were compared to patients with other PD's and healthy participants on implicit and explicit self-esteem. NPD patients did not differ in levels of explicit and implicit self-esteem compared to both the psychiatric and the healthy control group. Overall, the current study found no evidence in support of the mask model of narcissism among a clinical group. This implicates that it might not be relevant for clinicians to focus treatment of NPD on an underlying negative self-esteem. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A three dimensional multigrid multiblock multistage time stepping scheme for the Navier-Stokes equations

NASA Technical Reports Server (NTRS)

Elmiligui, Alaa; Cannizzaro, Frank; Melson, N. D.

1991-01-01

A general multiblock method for the solution of the three-dimensional, unsteady, compressible, thin-layer Navier-Stokes equations has been developed. The convective and pressure terms are spatially discretized using Roe's flux differencing technique while the viscous terms are centrally differenced. An explicit Runge-Kutta method is used to advance the solution in time. Local time stepping, adaptive implicit residual smoothing, and the Full Approximation Storage (FAS) multigrid scheme are added to the explicit time stepping scheme to accelerate convergence to steady state. Results for three-dimensional test cases are presented and discussed.

The Translated Dowling Polynomials and Numbers.

PubMed

Mangontarum, Mahid M; Macodi-Ringia, Amila P; Abdulcarim, Normalah S

2014-01-01

More properties for the translated Whitney numbers of the second kind such as horizontal generating function, explicit formula, and exponential generating function are proposed. Using the translated Whitney numbers of the second kind, we will define the translated Dowling polynomials and numbers. Basic properties such as exponential generating functions and explicit formula for the translated Dowling polynomials and numbers are obtained. Convexity, integral representation, and other interesting identities are also investigated and presented. We show that the properties obtained are generalizations of some of the known results involving the classical Bell polynomials and numbers. Lastly, we established the Hankel transform of the translated Dowling numbers.

Constant-pH Molecular Dynamics Study of Kyotorphin in an Explicit Bilayer

PubMed Central

Magalhães, Pedro R.; Machuqueiro, Miguel; Baptista, António M.

2015-01-01

To our knowledge, we present the first constant-pH molecular dynamics study of the neuropeptide kyotorphin in the presence of an explicit lipid bilayer. The overall conformation freedom of the peptide was found to be affected by the interaction with the membrane, in accordance with previous results using different methodologies. Analysis of the interactions between the N-terminus amine group of the peptide and several lipid atoms shows that the membrane is able to stabilize both ionized and neutral forms of kyotorphin, resulting in a pKa value that is similar to the one obtained in water. This illustrates how a detailed molecular model of the membrane leads to rather different results than would be expected from simply regarding it as a low-dielectric slab. PMID:25954885

Explicit Instructions Increase Cognitive Costs of Deception in Predictable Social Context

PubMed Central

Falkiewicz, Marcel; Sarzyńska, Justyna; Babula, Justyna; Szatkowska, Iwona; Grabowska, Anna; Nęcka, Edward

2015-01-01

Convincing participants to deceive remains one of the biggest and most important challenges of laboratory-based deception research. The simplest and most prevalent method involves explicitly instructing participants to lie or tell the truth before presenting each task item. The usual finding of such experiments is increased cognitive load associated with deceptive responses, explained by necessity to inhibit default and automatic honest responses. However, explicit instructions are usually coupled with the absence of social context in the experimental task. Context plays a key role in social cognition by activating prior knowledge, which facilitates behaviors consistent with the latter. We hypothesized that in the presence of social context, both honest and deceptive responses can be produced on the basis of prior knowledge, without reliance on truth and without additional cognitive load during deceptive responses. In order to test the hypothesis, we have developed Speed-Dating Task (SDT), which is based on a real-life social event. In SDT, participants respond both honestly and deceptively to questions in order to appear similar to each of the dates. The dates are predictable and represent well-known categories (i.e., atheist or conservative). In one condition participants rely on explicit instructions preceding each question (external cue). In the second condition no explicit instructions are present, so the participants need to adapt based on prior knowledge about the category the dates belong to (internal cue). With internal cues, reaction times (RTs) are similar for both honest and deceptive responses. However, in the presence of external cues (EC), RTs are longer for deceptive than honest responses, suggesting that deceptive responses are associated with increased cognitive load. Compared to internal cues, deception costs were higher when EC were present. However, the effect was limited to the first part of the experiment, only partially confirming our initial hypothesis. The results suggest that the presence of social context in deception tasks might have a significant influence on cognitive processes associated with deception. PMID:26696929

The Environment Makes a Difference: The Impact of Explicit and Implicit Attitudes as Precursors in Different Food Choice Tasks

PubMed Central

König, Laura M.; Giese, Helge; Schupp, Harald T.; Renner, Britta

2016-01-01

Studies show that implicit and explicit attitudes influence food choice. However, precursors of food choice often are investigated using tasks offering a very limited number of options despite the comparably complex environment surrounding real life food choice. In the present study, we investigated how the assortment impacts the relationship between implicit and explicit attitudes and food choice (confectionery and fruit), assuming that a more complex choice architecture is more taxing on cognitive resources. Specifically, a binary and a multiple option choice task based on the same stimulus set (fake food items) were presented to ninety-seven participants. Path modeling revealed that both explicit and implicit attitudes were associated with relative food choice (confectionery vs. fruit) in both tasks. In the binary option choice task, both explicit and implicit attitudes were significant precursors of food choice, with explicit attitudes having a greater impact. Conversely, in the multiple option choice task, the additive impact of explicit and implicit attitudes was qualified by an interaction indicating that, even if explicit and implicit attitudes toward confectionery were inconsistent, more confectionery was chosen than fruit if either was positive. This compensatory ‘one is sufficient’-effect indicates that the structure of the choice environment modulates the relationship between attitudes and choice. The study highlights that environmental constraints, such as the number of choice options, are an important boundary condition that need to be included when investigating the relationship between psychological precursors and behavior. PMID:27621719

The Environment Makes a Difference: The Impact of Explicit and Implicit Attitudes as Precursors in Different Food Choice Tasks.

PubMed

König, Laura M; Giese, Helge; Schupp, Harald T; Renner, Britta

2016-01-01

Studies show that implicit and explicit attitudes influence food choice. However, precursors of food choice often are investigated using tasks offering a very limited number of options despite the comparably complex environment surrounding real life food choice. In the present study, we investigated how the assortment impacts the relationship between implicit and explicit attitudes and food choice (confectionery and fruit), assuming that a more complex choice architecture is more taxing on cognitive resources. Specifically, a binary and a multiple option choice task based on the same stimulus set (fake food items) were presented to ninety-seven participants. Path modeling revealed that both explicit and implicit attitudes were associated with relative food choice (confectionery vs. fruit) in both tasks. In the binary option choice task, both explicit and implicit attitudes were significant precursors of food choice, with explicit attitudes having a greater impact. Conversely, in the multiple option choice task, the additive impact of explicit and implicit attitudes was qualified by an interaction indicating that, even if explicit and implicit attitudes toward confectionery were inconsistent, more confectionery was chosen than fruit if either was positive. This compensatory 'one is sufficient'-effect indicates that the structure of the choice environment modulates the relationship between attitudes and choice. The study highlights that environmental constraints, such as the number of choice options, are an important boundary condition that need to be included when investigating the relationship between psychological precursors and behavior.

Confusing Claims for Data: A Critique of Common Practices for Presenting Qualitative Research on Learning

ERIC Educational Resources Information Center

Hammer, David; Berland, Leema K.

2014-01-01

We question widely accepted practices of publishing articles that present quantified analyses of qualitative data. First, articles are often published that provide only very brief excerpts of the qualitative data themselves to illustrate the coding scheme, tacitly or explicitly treating the coding results as data. Second, articles are often…

Implicit/explicit memory versus analytic/nonanalytic processing: rethinking the mere exposure effect.

PubMed

Whittlesea, B W; Price, J R

2001-03-01

In studies of the mere exposure effect, rapid presentation of items can increase liking without accurate recognition. The effect on liking has been explained as a misattribution of fluency caused by prior presentation. However, fluency is also a source of feelings of familiarity. It is, therefore, surprising that prior experience can enhance liking without also causing familiarity-based recognition. We suggest that when study opportunities are minimal and test items are perceptually similar, people adopt an analytic approach, attempting to recognize distinctive features. That strategy fails because rapid presentation prevents effective encoding of such features; it also prevents people from experiencing fluency and a consequent feeling of familiarity. We suggest that the liking-without-recognition effect results from using an effective (nonanalytic) strategy in judging pleasantness, but an ineffective (analytic) strategy in recognition. Explanations of the mere exposure effect based on a distinction between implicit and explicit memory are unnecessary.

INVASIVE SPECIES: PREDICTING GEOGRAPHIC DISTRIBUTIONS USING ECOLOGICAL NICHE MODELING

EPA Science Inventory

Present approaches to species invasions are reactive in nature. This scenario results in management that perpetually lags behind the most recent invasion and makes control much more difficult. In contrast, spatially explicit ecological niche modeling provides an effective solut...

Advancing the Explicit Representation of Lake Processes in WRF-Hydro

NASA Astrophysics Data System (ADS)

Yates, D. N.; Read, L.; Barlage, M. J.; Gochis, D.

2017-12-01

Realistic simulation of physical processes in lakes is essential for closing the water and energy budgets in a coupled land-surface and hydrologic model, such as the Weather Research and Forecasting (WRF) model's WRF-Hydro framework. A current version of WRF-Hydro, the National Water Model (NWM), includes 1,506 waterbodies derived from the National Hydrography Database, each of which is modeled using a level-pool routing scheme. This presentation discusses the integration of WRF's one-dimensional lake model into WRF-Hydro, which is used to estimate waterbody fluxes and thus explicitly represent latent and sensible heat and the mass balance occurring over the lakes. Results of these developments are presented through a case study from Lake Winnebago, Wisconsin. Scalability and computational benchmarks to expand to the continental-scale NWM are discussed.

Racial bias in pain perception and response: experimental examination of automatic and deliberate processes.

PubMed

Mathur, Vani A; Richeson, Jennifer A; Paice, Judith A; Muzyka, Michael; Chiao, Joan Y

2014-05-01

Racial disparities in pain treatment pose a significant public health and scientific problem. Prior studies have demonstrated that clinicians and nonclinicians are less perceptive of, and suggest less treatment for, the pain of African Americans relative to European Americans. Here we investigate the effects of explicit/implicit patient race presentation, patient race, and perceiver race on pain perception and response. African American and European American participants rated pain perception, empathy, helping motivation, and treatment suggestion in response to vignettes about patients' pain. Vignettes were accompanied by a rapid (implicit) or static (explicit) presentation of an African or European American patient's face. Participants perceived and responded more to European American patients in the implicit prime condition, when the effect of patient race was below the level of conscious regulation. This effect was reversed when patient race was presented explicitly. Additionally, female participants perceived and responded more to the pain of all patients, relative to male participants, and in the implicit prime condition, African American participants were more perceptive and responsive than European Americans to the pain of all patients. Taken together, these results suggest that known disparities in pain treatment may be largely due to automatic (below the level of conscious regulation) rather than deliberate (subject to conscious regulation) biases. These biases were not associated with traditional implicit measures of racial attitudes, suggesting that biases in pain perception and response may be independent of general prejudice. Results suggest that racial biases in pain perception and treatment are at least partially due to automatic processes. When the relevance of patient race is made explicit, however, biases are attenuated and even reversed. We also find preliminary evidence that African Americans may be more sensitive to the pain of others than are European Americans. Copyright © 2014 American Pain Society. Published by Elsevier Inc. All rights reserved.

Implicit Knowledge, Explicit Knowledge, and Achievement in Second Language (L2) Spanish

ERIC Educational Resources Information Center

Gutierrez, Xavier

2012-01-01

Implicit and explicit knowledge of the second language (L2) are two central constructs in the field of second language acquisition (SLA). In recent years, there has been a renewed interest in obtaining valid and reliable measures of L2 learners' implicit and explicit knowledge (e.g., Bowles, 2011; R. Ellis, 2005). The purpose of the present study…

Deception Dissociates from False Belief Reasoning in Deaf Children: Implications for the Implicit versus Explicit Theory of Mind Distinction

ERIC Educational Resources Information Center

de Villiers, Peter A.; de Villiers, Jill G.

2012-01-01

Deception is a controversial aspect of theory of mind, and researchers disagree about whether it entails an understanding of the false beliefs of one's opponent. The present study asks whether children with delayed language and delayed explicit false belief reasoning can succeed on explicit deception tasks. Participants were 45 orally taught deaf…

Jump conditions in transonic equilibria

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

Guazzotto, L.; Betti, R.; Jardin, S. C.

2013-04-15

In the present paper, the numerical calculation of transonic equilibria, first introduced with the FLOW code in Guazzotto et al.[Phys. Plasmas 11, 604 (2004)], is critically reviewed. In particular, the necessity and effect of imposing explicit jump conditions at the transonic discontinuity are investigated. It is found that 'standard' (low-{beta}, large aspect ratio) transonic equilibria satisfy the correct jump condition with very good approximation even if the jump condition is not explicitly imposed. On the other hand, it is also found that high-{beta}, low aspect ratio equilibria require the correct jump condition to be explicitly imposed. Various numerical approaches aremore » described to modify FLOW to include the jump condition. It is proved that the new methods converge to the correct solution even in extreme cases of very large {beta}, while they agree with the results obtained with the old implementation of FLOW in lower-{beta} equilibria.« less

Connections with nature and environmental behaviors.

PubMed

Geng, Liuna; Xu, Jingke; Ye, Lijuan; Zhou, Wenjun; Zhou, Kexin

2015-01-01

The influence of environmental attitudes on environmental behaviors has long been discussed. However, few studies have addressed the foundation of such attitudes. In the present study, we explored primitive belief underlying environmental attitudes, i.e., connections with nature, and its relationship with pro-environmental behaviors. Specifically, we used scales, a computerized Implicit Association Test, and a situational simulation experiment to examine both explicit and implicit connections with nature, both deliberate and spontaneous environmental behaviors, and to find correlations between environmental connectedness and environmental behaviors. Results showed that explicit connectedness was positively correlated with deliberate environmental behaviors, while implicit connectedness was positively correlated with spontaneous environmental behaviors. Additionally, explicit and implicit connectedness was independent of each other. In conclusion, the current study confirms the positive role played by connections with nature in promoting environmental behavior, and accordingly suggests means to encourage pro-environmental behavior by enhancing people's connectedness to nature.

Connections with Nature and Environmental Behaviors

PubMed Central

Geng, Liuna; Xu, Jingke; Ye, Lijuan; Zhou, Wenjun; Zhou, Kexin

2015-01-01

The influence of environmental attitudes on environmental behaviors has long been discussed. However, few studies have addressed the foundation of such attitudes. In the present study, we explored primitive belief underlying environmental attitudes, i.e., connections with nature, and its relationship with pro-environmental behaviors. Specifically, we used scales, a computerized Implicit Association Test, and a situational simulation experiment to examine both explicit and implicit connections with nature, both deliberate and spontaneous environmental behaviors, and to find correlations between environmental connectedness and environmental behaviors. Results showed that explicit connectedness was positively correlated with deliberate environmental behaviors, while implicit connectedness was positively correlated with spontaneous environmental behaviors. Additionally, explicit and implicit connectedness was independent of each other. In conclusion, the current study confirms the positive role played by connections with nature in promoting environmental behavior, and accordingly suggests means to encourage pro-environmental behavior by enhancing people’s connectedness to nature. PMID:25985075

Presenting Lexical Bundles for Explicit Noticing with Schematic Linguistic Representation

ERIC Educational Resources Information Center

Thomson, Haidee Elizabeth

2016-01-01

Lexical bundles are essential for fluency, but their incompleteness is a stumbling block for learners. In this study, two presentation methods to increase awareness of lexical bundles through explicit noticing are explored and compared with incidental exposure. The three conditions in this study were as follows: noticing with schematic linguistic…

Implicit versus explicit momentum relaxation time solution for semiconductor nanowires

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

Marin, E. G., E-mail: egmarin@ugr.es; Ruiz, F. G., E-mail: franruiz@ugr.es; Godoy, A., E-mail: agodoy@ugr.es

2015-07-14

We discuss the necessity of the exact implicit Momentum Relaxation Time (MRT) solution of the Boltzmann transport equation in order to achieve reliable carrier mobility results in semiconductor nanowires. Firstly, the implicit solution for a 1D electron gas with a isotropic bandstructure is presented resulting in the formulation of a simple matrix system. Using this solution as a reference, the explicit approach is demonstrated to be inaccurate for the calculation of inelastic anisotropic mechanisms such as polar optical phonons, characteristic of III-V materials. Its validity for elastic and isotropic mechanisms is also evaluated. Finally, the implications of the MRT explicitmore » approach inaccuracies on the total mobility of Si and III-V NWs are studied.« less

Explicitly correlated coupled-cluster theory using cusp conditions. II. Treatment of connected triple excitations.

PubMed

Köhn, Andreas

2010-11-07

The coupled-cluster singles and doubles method augmented with single Slater-type correlation factors (CCSD-F12) determined by the cusp conditions (also denoted as SP ansatz) yields results close to the basis set limit with only small overhead compared to conventional CCSD. Quantitative calculations on many-electron systems, however, require to include the effect of connected triple excitations at least. In this contribution, the recently proposed [A. Köhn, J. Chem. Phys. 130, 131101 (2009)] extended SP ansatz and its application to the noniterative triples correction CCSD(T) is reviewed. The approach allows to include explicit correlation into connected triple excitations without introducing additional unknown parameters. The explicit expressions are presented and analyzed, and possible simplifications to arrive at a computationally efficient scheme are suggested. Numerical tests based on an implementation obtained by an automated approach are presented. Using a partial wave expansion for the neon atom, we can show that the proposed ansatz indeed leads to the expected (L(max)+1)(-7) convergence of the noniterative triples correction, where L(max) is the maximum angular momentum in the orbital expansion. Further results are reported for a test set of 29 molecules, employing Peterson's F12-optimized basis sets. We find that the customary approach of using the conventional noniterative triples correction on top of a CCSD-F12 calculation leads to significant basis set errors. This, however, is not always directly visible for total CCSD(T) energies due to fortuitous error compensation. The new approach offers a thoroughly explicitly correlated CCSD(T)-F12 method with improved basis set convergence of the triples contributions to both total and relative energies.

Explicit and inferred motives for nonsuicidal self-injurious acts and urges in borderline and avoidant personality disorders.

PubMed

Snir, Avigal; Rafaeli, Eshkol; Gadassi, Reuma; Berenson, Kathy; Downey, Geraldine

2015-07-01

Nonsuicidal self-injury (NSSI) is a perplexing phenomenon that may have differing motives. The present study used experience sampling methods (ESM) which inquired explicitly about the motives for NSSI, but also enabled a temporal examination of the antecedents/consequences of NSSI; these allow us to infer other motives which were not explicitly endorsed. Adults (n = 152, aged 18-65) with borderline personality disorder (BPD), avoidant personality disorder (APD), or no psychopathology participated in a 3-week computerized diary study. We examined 5 classes of explicit motives for engaging in NSSI, finding support primarily for internally directed rather than interpersonally directed ones. We then used multilevel regression to examine changes in affect, cognition, and behavior surrounding moments of NSSI acts/urges compared with control moments (i.e., without NSSI). We examined changes in 5 scales of inferred motives, designed to correspond to the 5 classes of explicit motives. The results highlight differing motives for NSSI among individuals with BPD and APD, with some similarities (mostly in the explicit motives) and some differences (mostly in the inferred motives) between the disorders. Despite their infrequent explicit endorsement, fluctuations in interpersonally oriented scales were found surrounding NSSI acts/urges. This highlights the need to continue attending to interpersonal aspects of NSSI in research and in clinical practice. Additionally, NSSI urges, like acts, were followed by decline in affective/interpersonal distress (although in a delayed manner). Thus, interventions that build distress tolerance and enhance awareness for affective changes, and for antecedent/consequence patterns in NSSI, could help individuals resist the urge to self-injure. (c) 2015 APA, all rights reserved).

The effects of eliciting implicit versus explicit social support among youths susceptible for late-onset smoking.

PubMed

Roberts, Megan E; Bernstein, Michael H; Colby, Suzanne M

2016-11-01

Adolescents susceptible to late-onset smoking (becoming regular smokers at age 18 or later) are an understudied population. Social support is a promising target for intervention, but it is important to distinguish between implicit social support (reminders that one belongs to a network of valued others) and explicit social support (seeking and receiving advice and emotional solace). This study aimed to test the potential protective influence of implicit and explicit social support on reducing the risk of late-onset smoking. Fifty-eight smoking-susceptible youths (aged 16-18, 45% African American, 55% non-Hispanic White) completed an experimental session that included a video-recording task designed to elicit thoughts about implicit, explicit, or no social support. Youths reported their behavioral willingness and intentions (BW and BI) to smoke immediately following the social support manipulation; a random sample of 39 youths reported again at a 3-week follow-up. Following the manipulation, BW and BI for cigarette smoking were significantly higher among youths assigned to the explicit-support condition, compared to those in the implicit-support or control conditions. At follow-up, BW and BI were highest in the explicit-support condition and lowest in the implicit-support condition, but the differences were not significant. Overall, findings indicated that for teens susceptible for late-onset smoking, eliciting thoughts about implicit social support produces lower risk for cigarette initiation than does eliciting thoughts about explicit social support. The present results and the video task that yielded them are important to researchers and practitioners interested in reducing the likelihood of late-onset smoking. Copyright © 2016 Elsevier Ltd. All rights reserved.

Attitude importance as a moderator of the relationship between implicit and explicit attitude measures.

PubMed

Karpinski, Andrew; Steinman, Ross B; Hilton, James L

2005-07-01

The authors examined attitude importance as a moderator of the relationship between the Implicit Association Test (IAT) and explicit attitude measures. In Study 1 (N = 194), as ratings of attitude importance regarding the 2000 presidential election increased, the strength of the relationship between a Bush-Gore IAT and explicit attitude measures also increased. Study 2 provided a conceptual replication of these results using attitudes toward Coke and Pepsi (N = 112). In addition, across both studies, explicit attitude measures were better predictors of deliberative behaviors than IAT scores. In Study 3 (N = 77), the authors examined the role of elaboration as a mechanism by which attitude importance may moderate IAT-explicit attitude correlations. As predicted, increased elaboration resulted in stronger IAT-explicit attitude correlations. Other possible mechanisms by which attitude importance may moderate the IAT-explicit attitude relationship also are discussed.

A CONCEPT MAP FOR INTEGRATED ENVIRONMENTAL ASSESSMENT AND FUTURES MODELING

EPA Science Inventory

Integrated assessment models are differentiated from other models by their explicit concern for results that are useful to decision makers. While the details will differ greatly for each particular integrated assessments project, there are certain concepts that will be present f...

Construction of stable explicit finite-difference schemes for Schroedinger type differential equations

NASA Technical Reports Server (NTRS)

Mickens, Ronald E.

1989-01-01

A family of conditionally stable, forward Euler finite difference equations can be constructed for the simplest equation of Schroedinger type, namely u sub t - iu sub xx. Generalization of this result to physically realistic Schroedinger type equations is presented.

The effect of gender stereotype activation on entrepreneurial intentions.

PubMed

Gupta, Vishal K; Turban, Daniel B; Bhawe, Nachiket M

2008-09-01

In this study, the impact of implicit and explicit activation of gender stereotypes on men's and women's intentions to pursue a traditionally masculine career, such as entrepreneurship, was examined. On the basis of stereotype activation theory, it was hypothesized that men and women would confirm the gender stereotype about entrepreneurship when it was presented implicitly but disconfirm it when it was presented explicitly. Hypotheses were tested by randomly assigning 469 business students to one of 6 experimental conditions and then measuring their entrepreneurial intentions. Results supported the hypothesis when entrepreneurship was associated with stereotypically masculine characteristics but not when it was associated with traditionally feminine characteristics. Men also had higher entrepreneurial intention scores compared with women when no stereotypical information about entrepreneurship was presented, suggesting that underlying societal stereotypes associating entrepreneurship with masculine characteristics may influence people's intentions. However, men and women reported similar intentions when entrepreneurship was presented as gender neutral, suggesting that widely held gender stereotypes can be nullified. Practical implications and directions for future research are discussed.

Ultrasonic modeling of an embedded elliptic crack

NASA Astrophysics Data System (ADS)

Fradkin, Larissa Ju.; Zalipaev, Victor

2000-05-01

Experiments indicate that the radiating near zone of a compressional circular transducer directly coupled to a homogeneous and isotropic solid has the following structure: there are geometrical zones where one can distinguish a plane compressional wave and toroidal waves, both compressional and shear, radiated by the transducer rim. As has been shown previously the modern diffraction theory allows to describe these explicitly. It also gives explicit asymptotic description of waves present in the transition zones. In case of a normal incidence of a plane compressional wave the explicit expressions have been obtained by Achenbach and co-authors for the fields diffracted by a penny-shaped crack. We build on the above work by applying the uniform GTD to model an oblique incidence of a plane compressional wave on an elliptical crack. We compare our asymptotic results with numerical results based on the boundary integral code as developed by Glushkovs, Krasnodar University, Russia. The asymptotic formulas form a basis of a code for high-frequency simulation of ultrasonic scattering by elliptical cracks situated in the vicinity of a compressional circular transducer, currently under development at our Center.

Large-Eddy Simulation of Subsonic Jets

NASA Astrophysics Data System (ADS)

Vuorinen, Ville; Wehrfritz, Armin; Yu, Jingzhou; Kaario, Ossi; Larmi, Martti; Boersma, Bendiks Jan

2011-12-01

The present study deals with development and validation of a fully explicit, compressible Runge-Kutta-4 (RK4) Navier-Stokes solver in the opensource CFD programming environment OpenFOAM. The background motivation is to shift towards explicit density based solution strategy and thereby avoid using the pressure based algorithms which are currently proposed in the standard OpenFOAM release for Large-Eddy Simulation (LES). This shift is considered necessary in strongly compressible flows when Ma > 0.5. Our application of interest is related to the pre-mixing stage in direct injection gas engines where high injection pressures are typically utilized. First, the developed flow solver is discussed and validated. Then, the implementation of subsonic inflow conditions using a forcing region in combination with a simplified nozzle geometry is discussed and validated. After this, LES of mixing in compressible, round jets at Ma = 0.3, 0.5 and 0.65 are carried out. Respectively, the Reynolds numbers of the jets correspond to Re = 6000, 10000 and 13000. Results for two meshes are presented. The results imply that the present solver produces turbulent structures, resolves a range of turbulent eddy frequencies and gives also mesh independent results within satisfactory limits for mean flow and turbulence statistics.

Not explicit but implicit memory is influenced by individual perception style

PubMed Central

Tsushima, Yoshiaki

2018-01-01

Not only explicit but also implicit memory has considerable influence on our daily life. However, it is still unclear whether explicit and implicit memories are sensitive to individual differences. Here, we investigated how individual perception style (global or local) correlates with implicit and explicit memory. As a result, we found that not explicit but implicit memory was affected by the perception style: local perception style people more greatly used implicit memory than global perception style people. These results help us to make the new effective application adapting to individual perception style and understand some clinical symptoms such as autistic spectrum disorder. Furthermore, this finding might give us new insight of memory involving consciousness and unconsciousness as well as relationship between implicit/explicit memory and individual perception style. PMID:29370212

Not explicit but implicit memory is influenced by individual perception style.

PubMed

Hine, Kyoko; Tsushima, Yoshiaki

2018-01-01

Not only explicit but also implicit memory has considerable influence on our daily life. However, it is still unclear whether explicit and implicit memories are sensitive to individual differences. Here, we investigated how individual perception style (global or local) correlates with implicit and explicit memory. As a result, we found that not explicit but implicit memory was affected by the perception style: local perception style people more greatly used implicit memory than global perception style people. These results help us to make the new effective application adapting to individual perception style and understand some clinical symptoms such as autistic spectrum disorder. Furthermore, this finding might give us new insight of memory involving consciousness and unconsciousness as well as relationship between implicit/explicit memory and individual perception style.

An Explicit Upwind Algorithm for Solving the Parabolized Navier-Stokes Equations

NASA Technical Reports Server (NTRS)

Korte, John J.

1991-01-01

An explicit, upwind algorithm was developed for the direct (noniterative) integration of the 3-D Parabolized Navier-Stokes (PNS) equations in a generalized coordinate system. The new algorithm uses upwind approximations of the numerical fluxes for the pressure and convection terms obtained by combining flux difference splittings (FDS) formed from the solution of an approximate Riemann (RP). The approximate RP is solved using an extension of the method developed by Roe for steady supersonic flow of an ideal gas. Roe's method is extended for use with the 3-D PNS equations expressed in generalized coordinates and to include Vigneron's technique of splitting the streamwise pressure gradient. The difficulty associated with applying Roe's scheme in the subsonic region is overcome. The second-order upwind differencing of the flux derivatives are obtained by adding FDS to either an original forward or backward differencing of the flux derivative. This approach is used to modify an explicit MacCormack differencing scheme into an upwind differencing scheme. The second order upwind flux approximations, applied with flux limiters, provide a method for numerically capturing shocks without the need for additional artificial damping terms which require adjustment by the user. In addition, a cubic equation is derived for determining Vegneron's pressure splitting coefficient using the updated streamwise flux vector. Decoding the streamwise flux vector with the updated value of Vigneron's pressure splitting improves the stability of the scheme. The new algorithm is applied to 2-D and 3-D supersonic and hypersonic laminar flow test cases. Results are presented for the experimental studies of Holden and of Tracy. In addition, a flow field solution is presented for a generic hypersonic aircraft at a Mach number of 24.5 and angle of attack of 1 degree. The computed results compare well to both experimental data and numerical results from other algorithms. Computational times required for the upwind PNS code are approximately equal to an explicit PNS MacCormack's code and existing implicit PNS solvers.

Symmetry Reductions and Group-Invariant Radial Solutions to the n-Dimensional Wave Equation

NASA Astrophysics Data System (ADS)

Feng, Wei; Zhao, Songlin

2018-01-01

In this paper, we derive explicit group-invariant radial solutions to a class of wave equation via symmetry group method. The optimal systems of one-dimensional subalgebras for the corresponding radial wave equation are presented in terms of the known point symmetries. The reductions of the radial wave equation into second-order ordinary differential equations (ODEs) with respect to each symmetry in the optimal systems are shown. Then we solve the corresponding reduced ODEs explicitly in order to write out the group-invariant radial solutions for the wave equation. Finally, several analytical behaviours and smoothness of the resulting solutions are discussed.

Improving Explicit Congestion Notification with the Mark-Front Strategy

NASA Technical Reports Server (NTRS)

Liu, Chunlei; Jain, Raj

2001-01-01

Delivering congestion signals is essential to the performance of networks. Current TCP/IP networks use packet losses to signal congestion. Packet losses not only reduces TCP performance, but also adds large delay. Explicit Congestion Notification (ECN) delivers a faster indication of congestion and has better performance. However, current ECN implementations mark the packet from the tail of the queue. In this paper, we propose the mark-front strategy to send an even faster congestion signal. We show that mark-front strategy reduces buffer size requirement, improves link efficiency and provides better fairness among users. Simulation results that verify our analysis are also presented.

Explicit and spontaneous retrieval of emotional scenes: electrophysiological correlates.

PubMed

Weymar, Mathias; Bradley, Margaret M; El-Hinnawi, Nasryn; Lang, Peter J

2013-10-01

When event-related potentials (ERP) are measured during a recognition task, items that have previously been presented typically elicit a larger late (400-800 ms) positive potential than new items. Recent data, however, suggest that emotional, but not neutral, pictures show ERP evidence of spontaneous retrieval when presented in a free-viewing task (Ferrari, Bradley, Codispoti, Karlsson, & Lang, 2012). In two experiments, we further investigated the brain dynamics of implicit and explicit retrieval. In Experiment 1, brain potentials were measured during a semantic categorization task, which did not explicitly probe episodic memory, but which, like a recognition task, required an active decision and a button press, and were compared to those elicited during recognition and free viewing. Explicit recognition prompted a late enhanced positivity for previously presented, compared with new, pictures regardless of hedonic content. In contrast, only emotional pictures showed an old-new difference when the task did not explicitly probe episodic memory, either when making an active categorization decision regarding picture content, or when simply viewing pictures. In Experiment 2, however, neutral pictures did prompt a significant old-new ERP difference during subsequent free viewing when emotionally arousing pictures were not included in the encoding set. These data suggest that spontaneous retrieval is heightened for salient cues, perhaps reflecting heightened attention and elaborative processing at encoding.

Explicit and spontaneous retrieval of emotional scenes: Electrophysiological correlates

PubMed Central

Weymar, Mathias; Bradley, Margaret M.; El-Hinnawi, Nasryn; Lang, Peter J.

2014-01-01

When event-related potentials are measured during a recognition task, items that have previously been presented typically elicit a larger late (400–800 ms) positive potential than new items. Recent data, however, suggest that emotional, but not neutral, pictures show ERP evidence of spontaneous retrieval when presented in a free-viewing task (Ferrari, Bradley, Codispoti & Lang, 2012). In two experiments, we further investigated the brain dynamics of implicit and explicit retrieval. In Experiment 1, brain potentials were measured during a semantic categorization task, which did not explicitly probe episodic memory, but which, like a recognition task, required an active decision and a button press, and were compared to those elicited during recognition and free viewing. Explicit recognition prompted a late enhanced positivity for previously presented, compared to new, pictures regardless of hedonic content. In contrast, only emotional pictures showed an old-new difference when the task did not explicitly probe episodic memory, either when either making an active categorization decision regarding picture content, or when simply viewing pictures. In Experiment 2, however, neutral pictures did prompt a significant old-new ERP difference during subsequent free viewing when emotionally arousing pictures were not included in the encoding set. These data suggest that spontaneous retrieval is heightened for salient cues, perhaps reflecting heightened attention and elaborative processing at encoding. PMID:23795588

Contributions from associative and explicit sequence knowledge to the execution of discrete keying sequences.

PubMed

Verwey, Willem B

2015-05-01

Research has provided many indications that highly practiced 6-key sequences are carried out in a chunking mode in which key-specific stimuli past the first are largely ignored. When in such sequences a deviating stimulus occasionally occurs at an unpredictable location, participants fall back to responding to individual stimuli (Verwey & Abrahamse, 2012). The observation that in such a situation execution still benefits from prior practice has been attributed to the possibility to operate in an associative mode. To better understand the contribution to the execution of keying sequences of motor chunks, associative sequence knowledge and also of explicit sequence knowledge, the present study tested three alternative accounts for the earlier finding of an execution rate increase at the end of 6-key sequences performed in the associative mode. The results provide evidence that the earlier observed execution rate increase can be attributed to the use of explicit sequence knowledge. In the present experiment this benefit was limited to sequences that are executed at the moderately fast rates of the associative mode, and occurred at both the earlier and final elements of the sequences. Copyright © 2015 Elsevier B.V. All rights reserved.

Boiling Temperature vs. Composition. An Almost-Exact Explicit Equation for a Binary Mixture Following Raoult's Law.

ERIC Educational Resources Information Center

Cardinali, Mario Emilio; Giomini, Claudio

1989-01-01

Proposes a simple procedure based on an expansion of the exponential terms of Raoult's law by applying it to the case of the benzene-toluene mixture. The results with experimental values are presented as a table. (YP)

The role of service areas in the optimization of FSS orbital and frequency assignments

NASA Technical Reports Server (NTRS)

Levis, C. A.; Wang, C.-W.; Yamamura, Y.; Reilly, C. H.; Gonsalvez, D. J.

1986-01-01

An implicit relationship is derived which relates the topocentric separation of two satellites required for a given level of single-entry protection to the separation and orientation of their service areas. The results are presented explicitly for circular beams and topocentric angles. A computational approach is given for elliptical beams and for use with longitude and latitude variables. It is found that the geocentric separation depends primarily on the service area separation, secondarily on a parameter which characterizes the electrical design, and only slightly on the mean orbital position of the satellites. Both linear programming and mixed integer programming algorithms are implemented. Possible objective function choices are discussed, and explicit formulations are presented for the choice of the sum of the absolute deviations of the orbital locations from some prescribed 'ideal' location set. A test problem involving six service areas is examined with results that are encouraging with respect to applying the linear programming procedure to larger scenarios.

Experiences with explicit finite-difference schemes for complex fluid dynamics problems on STAR-100 and CYBER-203 computers

NASA Technical Reports Server (NTRS)

Kumar, A.; Rudy, D. H.; Drummond, J. P.; Harris, J. E.

1982-01-01

Several two- and three-dimensional external and internal flow problems solved on the STAR-100 and CYBER-203 vector processing computers are described. The flow field was described by the full Navier-Stokes equations which were then solved by explicit finite-difference algorithms. Problem results and computer system requirements are presented. Program organization and data base structure for three-dimensional computer codes which will eliminate or improve on page faulting, are discussed. Storage requirements for three-dimensional codes are reduced by calculating transformation metric data in each step. As a result, in-core grid points were increased in number by 50% to 150,000, with a 10% execution time increase. An assessment of current and future machine requirements shows that even on the CYBER-205 computer only a few problems can be solved realistically. Estimates reveal that the present situation is more storage limited than compute rate limited, but advancements in both storage and speed are essential to realistically calculate three-dimensional flow.

Using implicit attitudes of exercise importance to predict explicit exercise dependence symptoms and exercise behaviors

PubMed Central

Forrest, Lauren N.; Smith, April R.; Fussner, Lauren M.; Dodd, Dorian R.; Clerkin, Elise M.

2015-01-01

Objectives ”Fast” (i.e., implicit) processing is relatively automatic; “slow” (i.e., explicit) processing is relatively controlled and can override automatic processing. These different processing types often produce different responses that uniquely predict behaviors. In the present study, we tested if explicit, self-reported symptoms of exercise dependence and an implicit association of exercise as important predicted exercise behaviors and change in problematic exercise attitudes. Design We assessed implicit attitudes of exercise importance and self-reported symptoms of exercise dependence at Time 1. Participants reported daily exercise behaviors for approximately one month, and then completed a Time 2 assessment of self-reported exercise dependence symptoms. Method Undergraduate males and females (Time 1, N = 93; Time 2, N = 74) tracked daily exercise behaviors for one month and completed an Implicit Association Test assessing implicit exercise importance and subscales of the Exercise Dependence Questionnaire (EDQ) assessing exercise dependence symptoms. Results Implicit attitudes of exercise importance and Time 1 EDQ scores predicted Time 2 EDQ scores. Further, implicit exercise importance and Time 1 EDQ scores predicted daily exercise intensity while Time 1 EDQ scores predicted the amount of days exercised. Conclusion Implicit and explicit processing appear to uniquely predict exercise behaviors and attitudes. Given that different implicit and explicit processes may drive certain exercise factors (e.g., intensity and frequency, respectively), these behaviors may contribute to different aspects of exercise dependence. PMID:26195916

Implicit Associations and Explicit Expectancies toward Cannabis in Heavy Cannabis Users and Controls

PubMed Central

Beraha, Esther M.; Cousijn, Janna; Hermanides, Elisa; Goudriaan, Anna E.; Wiers, Reinout W.

2013-01-01

Cognitive biases, including implicit memory associations are thought to play an important role in the development of addictive behaviors. The aim of the present study was to investigate implicit affective memory associations in heavy cannabis users. Implicit positive-arousal, sedation, and negative associations toward cannabis were measured with three Single Category Implicit Association Tests (SC-IAT’s) and compared between 59 heavy cannabis users and 89 controls. Moreover, we investigated the relationship between these implicit affective associations and explicit expectancies, subjective craving, cannabis use, and cannabis related problems. Results show that heavy cannabis users had stronger implicit positive-arousal associations but weaker implicit negative associations toward cannabis compared to controls. Moreover, heavy cannabis users had stronger sedation but weaker negative explicit expectancies toward cannabis compared to controls. Within heavy cannabis users, more cannabis use was associated with stronger implicit negative associations whereas more cannabis use related problems was associated with stronger explicit negative expectancies, decreasing the overall difference on negative associations between cannabis users and controls. No other associations were observed between implicit associations, explicit expectancies, measures of cannabis use, cannabis use related problems, or subjective craving. These findings indicate that, in contrast to other substances of abuse like alcohol and tobacco, the relationship between implicit associations and cannabis use appears to be weak in heavy cannabis users. PMID:23801968

Cue-induced activation of implicit affective associations with heroin use in abstinent heroin abusers.

PubMed

Chen, Jianyong; Wang, Xuan; Zhang, Meng; Zhang, Feng; Shen, Mowei

2015-06-01

While drug-related contexts have been shown to influence drug users' implicit and explicit drug-related cognitions, this has been minimally explored in heroin abusers. This study examined the effect of heroin-related cue exposure on implicit and explicit valence and arousal-sedation associations with heroin use for abstinent heroin abusers. In Experiment 1, 39 male abstinent heroin abusers were exposed to heroin-related words and reported cravings before and after cue exposure. They subsequently performed two Extrinsic Affective Simon Tasks (EASTs), which were used to assess implicit valence and arousal-sedation associations with heroin use. Thirty-six male abstinent heroin abusers (controls) only performed the two EASTs. All participants completed measures of explicit expectancy regarding heroin use. In Experiment 2, twenty-eight newly recruited abstinent heroin abusers were exposed to heroin-related pictures, and completed the same implicit and explicit measures used in Experiment 1. A non-significant increase in craving after cue exposure was observed. While participants exposed to heroin-related words or pictures exhibited more positive implicit heroin use associations (relative to negative associations), and such trend was not observed in controls, this difference was not significant across groups. Participants still indicated negative explicit associations with heroin use after cue exposure. Exposure to cues significantly accelerated arousal and sedation responses. Whether cue exposure could change self-reported craving requires further study in abstinent heroin abusers. The exclusively male sample limits generalization of the results. The present findings extend the evidence on whether implicit and explicit heroin-related cognitions are susceptible to context. Copyright © 2014 Elsevier Ltd. All rights reserved.

Decreased response inhibition to sad faces during explicit and implicit tasks in females with depression: Evidence from an event-related potential study.

PubMed

Yu, Fengqiong; Zhou, Xiaoqing; Qing, Wu; Li, Dan; Li, Jing; Chen, Xingui; Ji, Gongjun; Dong, Yi; Luo, Yuejia; Zhu, Chunyan; Wang, Kai

2017-01-30

The present study aimed to investigate neural substrates of response inhibition to sad faces across explicit and implicit tasks in depressed female patients. Event-related potentials were obtained while participants performed modified explicit and implicit emotional go/no-go tasks. Compared to controls, depressed patients showed decreased discrimination accuracy and amplitudes of original and nogo-go difference waves at the P3 interval in response inhibition to sad faces during explicit and implicit tasks. P3 difference wave were positively correlated with discrimination accuracy and were independent of clinical assessment. The activation of right dorsal prefrontal cortex was larger for the implicit than for the explicit task in sad condition in health controls, but was similar for the two tasks in depressed patients. The present study indicated that selectively impairment in response inhibition to sad faces in depressed female patients occurred at the behavior inhibition stage across implicit and explicit tasks and may be a trait-like marker of depression. Longitudinal studies are required to determine whether decreased response inhibition to sad faces increases the risk for future depressive episodes so that appropriate treatment can be administered to patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Incidental Learning and Explicit Recall in Upper Extremity Prosthesis Use: Insights Into Functional Rehabilitation Challenges.

PubMed

Hughey, Laura; Wheaton, Lewis A

2016-01-01

Loss of an upper extremity and the resulting rehabilitation often requires individuals to learn how to use a prosthetic device for activities of daily living. It remains unclear how prostheses affect motor learning outcomes. The authors' aim was to evaluate whether incidental motor learning and explicit recall is affected in intact persons either using prostheses (n = 10) or the sound limb (n = 10), and a chronic amputee on a modified serial reaction time task. Latency and accuracy of task completion were recorded over six blocks, with a distractor task between blocks 5 and 6. Participants were also asked to recall the sequence immediately following the study and at a 24-hr follow-up. Prosthesis users demonstrate patterns consistent with implicit learning, with sustained error patterns with the distal terminal device. More intact individuals were able to explicitly recall the sequence initially, however there was no significant difference 24 hr following the study. Acute incidental motor learning does not appear to diminish task related error patterns or accompany with explicit recall in prosthesis users, which could present limitations for acute training of prosthesis use in amputees. This suggests differing mechanisms of visuospatial sequential learning and motor control with prostheses.

Investigating the predictive validity of implicit and explicit measures of motivation in problem-solving behavioural tasks.

PubMed

Keatley, David; Clarke, David D; Hagger, Martin S

2013-09-01

Research into the effects of individuals'autonomous motivation on behaviour has traditionally adopted explicit measures and self-reported outcome assessment. Recently, there has been increased interest in the effects of implicit motivational processes underlying behaviour from a self-determination theory (SDT) perspective. The aim of the present research was to provide support for the predictive validity of an implicit measure of autonomous motivation on behavioural persistence on two objectively measurable tasks. SDT and a dual-systems model were adopted as frameworks to explain the unique effects offered by explicit and implicit autonomous motivational constructs on behavioural persistence. In both studies, implicit autonomous motivation significantly predicted unique variance in time spent on each task. Several explicit measures of autonomous motivation also significantly predicted persistence. Results provide support for the proposed model and the inclusion of implicit measures in research on motivated behaviour. In addition, implicit measures of autonomous motivation appear to be better suited to explaining variance in behaviours that are more spontaneous or unplanned. Future implications for research examining implicit motivation from dual-systems models and SDT approaches are outlined. © 2012 The British Psychological Society.

Emergence of a coherent and cohesive swarm based on mutual anticipation

PubMed Central

Murakami, Hisashi; Niizato, Takayuki; Gunji, Yukio-Pegio

2017-01-01

Collective behavior emerging out of self-organization is one of the most striking properties of an animal group. Typically, it is hypothesized that each individual in an animal group tends to align its direction of motion with those of its neighbors. Most previous models for collective behavior assume an explicit alignment rule, by which an agent matches its velocity with that of neighbors in a certain neighborhood, to reproduce a collective order pattern by simple interactions. Recent empirical studies, however, suggest that there is no evidence for explicit matching of velocity, and that collective polarization arises from interactions other than those that follow the explicit alignment rule. We here propose a new lattice-based computational model that does not incorporate the explicit alignment rule but is based instead on mutual anticipation and asynchronous updating. Moreover, we show that this model can realize densely collective motion with high polarity. Furthermore, we focus on the behavior of a pair of individuals, and find that the turning response is drastically changed depending on the distance between two individuals rather than the relative heading, and is consistent with the empirical observations. Therefore, the present results suggest that our approach provides an alternative model for collective behavior. PMID:28406173

Generalized Linear Covariance Analysis

NASA Technical Reports Server (NTRS)

Carpenter, James R.; Markley, F. Landis

2014-01-01

This talk presents a comprehensive approach to filter modeling for generalized covariance analysis of both batch least-squares and sequential estimators. We review and extend in two directions the results of prior work that allowed for partitioning of the state space into solve-for'' and consider'' parameters, accounted for differences between the formal values and the true values of the measurement noise, process noise, and textita priori solve-for and consider covariances, and explicitly partitioned the errors into subspaces containing only the influence of the measurement noise, process noise, and solve-for and consider covariances. In this work, we explicitly add sensitivity analysis to this prior work, and relax an implicit assumption that the batch estimator's epoch time occurs prior to the definitive span. We also apply the method to an integrated orbit and attitude problem, in which gyro and accelerometer errors, though not estimated, influence the orbit determination performance. We illustrate our results using two graphical presentations, which we call the variance sandpile'' and the sensitivity mosaic,'' and we compare the linear covariance results to confidence intervals associated with ensemble statistics from a Monte Carlo analysis.

The number of reduced alignments between two DNA sequences

PubMed Central

2014-01-01

Background In this study we consider DNA sequences as mathematical strings. Total and reduced alignments between two DNA sequences have been considered in the literature to measure their similarity. Results for explicit representations of some alignments have been already obtained. Results We present exact, explicit and computable formulas for the number of different possible alignments between two DNA sequences and a new formula for a class of reduced alignments. Conclusions A unified approach for a wide class of alignments between two DNA sequences has been provided. The formula is computable and, if complemented by software development, will provide a deeper insight into the theory of sequence alignment and give rise to new comparison methods. AMS Subject Classification Primary 92B05, 33C20, secondary 39A14, 65Q30 PMID:24684679

Implicit and Explicit Mechanisms of Word Learning in a Narrative Context: An Event-Related Potential Study

ERIC Educational Resources Information Center

Batterink, Laura; Neville, Helen

2011-01-01

The vast majority of word meanings are learned simply by extracting them from context rather than by rote memorization or explicit instruction. Although this skill is remarkable, little is known about the brain mechanisms involved. In the present study, ERPs were recorded as participants read stories in which pseudowords were presented multiple…

Explicit and implicit cognition: a preliminary test of a dual-process theory of cognitive vulnerability to depression.

PubMed

Haeffel, Gerald J; Abramson, Lyn Y; Brazy, Paige C; Shah, James Y; Teachman, Bethany A; Nosek, Brian A

2007-06-01

Two studies were conducted to test a dual-process theory of cognitive vulnerability to depression. According to this theory, implicit and explicit cognitive processes have differential effects on depressive reactions to stressful life events. Implicit processes are hypothesized to be critical in determining an individual's immediate affective reaction to stress whereas explicit cognitions are thought to be more involved in long-term depressive reactions. Consistent with hypotheses, the results of study 1 (cross-sectional; N=237) showed that implicit, but not explicit, cognitions predicted immediate affective reactions to a lab stressor. Study 2 (longitudinal; N=251) also supported the dual-process model of cognitive vulnerability to depression. Results showed that both the implicit and explicit measures interacted with life stress to predict prospective changes in depressive symptoms, respectively. However, when both implicit and explicit predictors were entered into a regression equation simultaneously, only the explicit measure interacted with stress to remain a unique predictor of depressive symptoms over the five-week prospective interval.

Improving carbon monitoring and reporting in forests using spatially-explicit information.

PubMed

Boisvenue, Céline; Smiley, Byron P; White, Joanne C; Kurz, Werner A; Wulder, Michael A

2016-12-01

Understanding and quantifying carbon (C) exchanges between the biosphere and the atmosphere-specifically the process of C removal from the atmosphere, and how this process is changing-is the basis for developing appropriate adaptation and mitigation strategies for climate change. Monitoring forest systems and reporting on greenhouse gas (GHG) emissions and removals are now required components of international efforts aimed at mitigating rising atmospheric GHG. Spatially-explicit information about forests can improve the estimates of GHG emissions and removals. However, at present, remotely-sensed information on forest change is not commonly integrated into GHG reporting systems. New, detailed (30-m spatial resolution) forest change products derived from satellite time series informing on location, magnitude, and type of change, at an annual time step, have recently become available. Here we estimate the forest GHG balance using these new Landsat-based change data, a spatial forest inventory, and develop yield curves as inputs to the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) to estimate GHG emissions and removals at a 30 m resolution for a 13 Mha pilot area in Saskatchewan, Canada. Our results depict the forests as cumulative C sink (17.98 Tg C or 0.64 Tg C year -1 ) between 1984 and 2012 with an average C density of 206.5 (±0.6) Mg C ha -1 . Comparisons between our estimates and estimates from Canada's National Forest Carbon Monitoring, Accounting and Reporting System (NFCMARS) were possible only on a subset of our study area. In our simulations the area was a C sink, while the official reporting simulations, it was a C source. Forest area and overall C stock estimates also differ between the two simulated estimates. Both estimates have similar uncertainties, but the spatially-explicit results we present here better quantify the potential improvement brought on by spatially-explicit modelling. We discuss the source of the differences between these estimates. This study represents an important first step towards the integration of spatially-explicit information into Canada's NFCMARS.

Slater-type geminals in explicitly-correlated perturbation theory: application to n-alkanols and analysis of errors and basis-set requirements.

PubMed

Höfener, Sebastian; Bischoff, Florian A; Glöss, Andreas; Klopper, Wim

2008-06-21

In the recent years, Slater-type geminals (STGs) have been used with great success to expand the first-order wave function in an explicitly-correlated perturbation theory. The present work reports on this theory's implementation in the framework of the Turbomole suite of programs. A formalism is presented for evaluating all of the necessary molecular two-electron integrals by means of the Obara-Saika recurrence relations, which can be applied when the STG is expressed as a linear combination of a small number (n) of Gaussians (STG-nG geminal basis). In the Turbomole implementation of the theory, density fitting is employed and a complementary auxiliary basis set (CABS) is used for the resolution-of-the-identity (RI) approximation of explicitly-correlated theory. By virtue of this RI approximation, the calculation of molecular three- and four-electron integrals is avoided. An approximation is invoked to avoid the two-electron integrals over the commutator between the operators of kinetic energy and the STG. This approximation consists of computing commutators between matrices in place of operators. Integrals over commutators between operators would have occurred if the theory had been formulated and implemented as proposed originally. The new implementation in Turbomole was tested by performing a series of calculations on rotational conformers of the alkanols n-propanol through n-pentanol. Basis-set requirements concerning the orbital basis, the auxiliary basis set for density fitting and the CABS were investigated. Furthermore, various (constrained) optimizations of the amplitudes of the explicitly-correlated double excitations were studied. These amplitudes can be optimized in orbital-variant and orbital-invariant manners, or they can be kept fixed at the values governed by the rational generator approach, that is, by the electron cusp conditions. Electron-correlation effects beyond the level of second-order perturbation theory were accounted for by conventional coupled-cluster calculations with single, double and perturbative triple excitations [CCSD(T)]. The explicitly-correlated perturbation theory results were combined with CCSD(T) results and compared with literature data obtained by basis-set extrapolation.

Flavour chemicals in a sample of non-cigarette tobacco products without explicit flavour names sold in New York City in 2015

PubMed Central

Farley, Shannon M; Schroth, Kevin RJ; Grimshaw, Victoria; Luo, Wentai; DeGagne, Julia L; Tierney, Peyton A; Kim, Kilsun; Pankow, James F

2018-01-01

Background Youth who experiment with tobacco often start with flavoured products. In New York City (NYC), local law restricts sales of all tobacco products with ‘characterising flavours’ except for ‘tobacco, menthol, mint and wintergreen’. Enforcement is based on packaging: explicit use of a flavour name (eg, ‘strawberry’) or image depicting a flavour (eg, a fruit) is presumptive evidence that a product is flavoured and therefore prohibited. However, a tobacco product may contain significant levels of added flavour chemicals even when the label does not explicitly use a flavour name. Methods Sixteen tobacco products were purchased within NYC in 2015 that did not have explicit flavour names, along with three with flavour names. These were analysed for 92 known flavour chemicals plus triacetin by gas chromatography/mass spectrometry. Results 14 of the 16 products had total determined flavour chemical levels that were higher (>0.3 mg/g) than in previously studied flavour-labelled products and of a chemical profile indicating added flavour chemicals. Conclusions The results suggest that the tobacco industry has responded to sales restrictions by renaming flavoured products to avoid explicitly identifying them as flavoured. While chemical analysis is the most precise means of identifying flavours in tobacco products, federal tobacco laws pre-empt localities from basing regulations on that approach, limiting enforcement options. If the Food and Drug Administration would mandate that all tobacco products must indicate when flavourings are present above a specific level, local jurisdictions could enforce their sales restrictions. A level of 0.1 mg/g for total added flavour chemicals is suggested here as a relevant reference value for regulating added flavour chemicals in tobacco products. PMID:28400490

Corruption of accuracy and efficiency of Markov chain Monte Carlo simulation by inaccurate numerical implementation of conceptual hydrologic models

NASA Astrophysics Data System (ADS)

Schoups, G.; Vrugt, J. A.; Fenicia, F.; van de Giesen, N. C.

2010-10-01

Conceptual rainfall-runoff models have traditionally been applied without paying much attention to numerical errors induced by temporal integration of water balance dynamics. Reliance on first-order, explicit, fixed-step integration methods leads to computationally cheap simulation models that are easy to implement. Computational speed is especially desirable for estimating parameter and predictive uncertainty using Markov chain Monte Carlo (MCMC) methods. Confirming earlier work of Kavetski et al. (2003), we show here that the computational speed of first-order, explicit, fixed-step integration methods comes at a cost: for a case study with a spatially lumped conceptual rainfall-runoff model, it introduces artificial bimodality in the marginal posterior parameter distributions, which is not present in numerically accurate implementations of the same model. The resulting effects on MCMC simulation include (1) inconsistent estimates of posterior parameter and predictive distributions, (2) poor performance and slow convergence of the MCMC algorithm, and (3) unreliable convergence diagnosis using the Gelman-Rubin statistic. We studied several alternative numerical implementations to remedy these problems, including various adaptive-step finite difference schemes and an operator splitting method. Our results show that adaptive-step, second-order methods, based on either explicit finite differencing or operator splitting with analytical integration, provide the best alternative for accurate and efficient MCMC simulation. Fixed-step or adaptive-step implicit methods may also be used for increased accuracy, but they cannot match the efficiency of adaptive-step explicit finite differencing or operator splitting. Of the latter two, explicit finite differencing is more generally applicable and is preferred if the individual hydrologic flux laws cannot be integrated analytically, as the splitting method then loses its advantage.

ADVANCED URBANIZED METEOROLOGICAL MODELING AND AIR QUALITY SIMULATIONS WITH CMAQ AT NEIGHBORHOOD SCALES

EPA Science Inventory

We present results from a study testing the new boundary layer parameterization method, the canopy drag approach (DA) which is designed to explicitly simulate the effects of buildings, street and tree canopies on the dynamic, thermodynamic structure and dispersion fields in urban...

Testing memory for unseen visual stimuli in patients with extinction and spatial neglect.

PubMed

Vuilleumier, Patrik; Schwartz, Sophie; Clarke, Karen; Husain, Masud; Driver, Jon

2002-08-15

Visual extinction after right parietal damage involves a loss of awareness for stimuli in the contralesional field when presented concurrently with ipsilesional stimuli, although contralesional stimuli are still perceived if presented alone. However, extinguished stimuli can still receive some residual on-line processing, without awareness. Here we examined whether such residual processing of extinguished stimuli can produce implicit and/or explicit memory traces lasting many minutes. We tested four patients with right parietal damage and left extinction on two sessions, each including distinct study and subsequent test phases. At study, pictures of objects were shown briefly in the right, left, or both fields. Patients were asked to name them without memory instructions (Session 1) or to make an indoor/outdoor categorization and memorize them (Session 2). They extinguished most left stimuli on bilateral presentation. During the test (up to 48 min later), fragmented pictures of the previously exposed objects (or novel objects) were presented alone in either field. Patients had to identify each object and then judge whether it had previously been exposed. Identification of fragmented pictures was better for previously exposed objects that had been consciously seen and critically also for objects that had been extinguished (as compared with novel objects), with no influence of the depth of processing during study. By contrast, explicit recollection occurred only for stimuli that were consciously seen at study and increased with depth of processing. These results suggest implicit but not explicit memory for extinguished visual stimuli in parietal patients.

True and False DRM Memories: Differences Detected with an Implicit Task

PubMed Central

Marini, Maddalena; Agosta, Sara; Mazzoni, Giuliana; Barba, Gianfranco Dalla; Sartori, Giuseppe

2012-01-01

Memory is prone to illusions. When people are presented with lists of words associated with a non-presented critical lure, they produce a high level of false recognitions (false memories) for non-presented related stimuli indistinguishable, at the explicit level, from presented words (DRM paradigm). We assessed whether true and false DRM memories can be distinguished at the implicit level by using the autobiographical IAT (aIAT), a novel method based on indirect measures that permits to detect true autobiographical events encoded in the respondent’s mind/brain. In our experiment, after a DRM task participants performed two aIATs: the first aimed at testing implicit memory for presented words (true-memories aIAT) and the second aimed at evaluating implicit memory for critical lures (false-memories aIAT). Specifically, the two aIATs assessed the association of presented words and critical lures with the logical dimension “true.” Results showed that the aIAT detected a greater association of presented words than critical lures with the logical dimension “true.” This result indicates that although true and false DRM memories are indistinguishable at the explicit level a different association of the true and false DRM memories with the logical dimension “true” can be detected at the implicit level, and suggests that the aIAT may be a sensitive instrument to detect differences between true and false DRM memories. PMID:22969740

Achieving enlightenment: what do we know about the implicit learning system and its interaction with explicit knowledge?

PubMed

Vidoni, Eric D; Boyd, Lara A

2007-09-01

Two major memory and learning systems operate in the brain: one for facts and ideas (ie, the declarative or explicit system), one for habits and behaviors (ie, the procedural or implicit system). Broadly speaking these two memory systems can operate either in concert or entirely independently of one another during the performance and learning of skilled motor behaviors. This Special Issue article has two parts. In the first, we present a review of implicit motor skill learning that is largely centered on the interactions between declarative and procedural learning and memory. Because distinct neuroanatomical substrates support unique aspects of learning and memory and thus focal injury can cause impairments that are dependent on lesion location, we also broadly consider which brain regions mediate implicit and explicit learning and memory. In the second part of this article, the interactive nature of these two memory systems is illustrated by the presentation of new data that reveal that both learning implicitly and acquiring explicit knowledge through physical practice lead to motor sequence learning. In our new data, we discovered that for healthy individuals use of the implicit versus explicit memory system differently affected variability of performance during acquisition practice; variability was higher early in practice for the implicit group and later in practice for the acquired explicit group. Despite the difference in performance variability, by retention both groups demonstrated comparable change in tracking accuracy and thus, motor sequence learning. Clinicians should be aware of the potential effects of implicit and explicit interactions when designing rehabilitation interventions, particularly when delivering explicit instructions before task practice, working with individuals with focal brain damage, and/or adjusting therapeutic parameters based on acquisition performance variability.

Late positive potential to explicit sexual images associated with the number of sexual intercourse partners

PubMed Central

Steele, Vaughn R.; Staley, Cameron; Sabatinelli, Dean

2015-01-01

Risky sexual behaviors typically occur when a person is sexually motivated by potent, sexual reward cues. Yet, individual differences in sensitivity to sexual cues have not been examined with respect to sexual risk behaviors. A greater responsiveness to sexual cues might provide greater motivation for a person to act sexually; a lower responsiveness to sexual cues might lead a person to seek more intense, novel, possibly risky, sexual acts. In this study, event-related potentials were recorded in 64 men and women while they viewed a series of emotional, including explicit sexual, photographs. The motivational salience of the sexual cues was varied by including more and less explicit sexual images. Indeed, the more explicit sexual stimuli resulted in enhanced late positive potentials (LPP) relative to the less explicit sexual images. Participants with fewer sexual intercourse partners in the last year had reduced LPP amplitude to the less explicit sexual images than the more explicit sexual images, whereas participants with more partners responded similarly to the more and less explicit sexual images. This pattern of results is consistent with a greater responsivity model. Those who engage in more sexual behaviors consistent with risk are also more responsive to less explicit sexual cues. PMID:24526189

Improving benchmarking by using an explicit framework for the development of composite indicators: an example using pediatric quality of care

PubMed Central

2010-01-01

Background The measurement of healthcare provider performance is becoming more widespread. Physicians have been guarded about performance measurement, in part because the methodology for comparative measurement of care quality is underdeveloped. Comprehensive quality improvement will require comprehensive measurement, implying the aggregation of multiple quality metrics into composite indicators. Objective To present a conceptual framework to develop comprehensive, robust, and transparent composite indicators of pediatric care quality, and to highlight aspects specific to quality measurement in children. Methods We reviewed the scientific literature on composite indicator development, health systems, and quality measurement in the pediatric healthcare setting. Frameworks were selected for explicitness and applicability to a hospital-based measurement system. Results We synthesized various frameworks into a comprehensive model for the development of composite indicators of quality of care. Among its key premises, the model proposes identifying structural, process, and outcome metrics for each of the Institute of Medicine's six domains of quality (safety, effectiveness, efficiency, patient-centeredness, timeliness, and equity) and presents a step-by-step framework for embedding the quality of care measurement model into composite indicator development. Conclusions The framework presented offers researchers an explicit path to composite indicator development. Without a scientifically robust and comprehensive approach to measurement of the quality of healthcare, performance measurement will ultimately fail to achieve its quality improvement goals. PMID:20181129

Accurate forced-choice recognition without awareness of memory retrieval.

PubMed

Voss, Joel L; Baym, Carol L; Paller, Ken A

2008-06-01

Recognition confidence and the explicit awareness of memory retrieval commonly accompany accurate responding in recognition tests. Memory performance in recognition tests is widely assumed to measure explicit memory, but the generality of this assumption is questionable. Indeed, whether recognition in nonhumans is always supported by explicit memory is highly controversial. Here we identified circumstances wherein highly accurate recognition was unaccompanied by hallmark features of explicit memory. When memory for kaleidoscopes was tested using a two-alternative forced-choice recognition test with similar foils, recognition was enhanced by an attentional manipulation at encoding known to degrade explicit memory. Moreover, explicit recognition was most accurate when the awareness of retrieval was absent. These dissociations between accuracy and phenomenological features of explicit memory are consistent with the notion that correct responding resulted from experience-dependent enhancements of perceptual fluency with specific stimuli--the putative mechanism for perceptual priming effects in implicit memory tests. This mechanism may contribute to recognition performance in a variety of frequently-employed testing circumstances. Our results thus argue for a novel view of recognition, in that analyses of its neurocognitive foundations must take into account the potential for both (1) recognition mechanisms allied with implicit memory and (2) recognition mechanisms allied with explicit memory.

Matrix elements of explicitly correlated Gaussian basis functions with arbitrary angular momentum

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

Joyce, Tennesse; Varga, Kálmán

2016-05-14

A new algorithm for calculating the Hamiltonian matrix elements with all-electron explicitly correlated Gaussian functions for quantum-mechanical calculations of atoms with arbitrary angular momentum is presented. The calculations are checked on several excited states of three and four electron systems. The presented formalism can be used as unified framework for high accuracy calculations of properties of small atoms and molecules.

The Effect of Implicit and Explicit Feedback: A Study on the Acquisition of Mandarin Classifiers by Chinese Heritage and Non-Heritage Language Learners

ERIC Educational Resources Information Center

Han, Ye

2010-01-01

Previous studies revealed mixed results in terms of the relative effects of implicit and explicit feedback: some found that explicit feedback worked more efficiently than implicit feedback; others found no difference between the two feedback types. These contrasting results called for further investigations into this issue, particularly examining…

Attention and perceptual implicit memory: effects of selective versus divided attention and number of visual objects.

PubMed

Mulligan, Neil W

2002-08-01

Extant research presents conflicting results on whether manipulations of attention during encoding affect perceptual priming. Two suggested mediating factors are type of manipulation (selective vs divided) and whether attention is manipulated across multiple objects or within a single object. Words printed in different colors (Experiment 1) or flanked by colored blocks (Experiment 2) were presented at encoding. In the full-attention condition, participants always read the word, in the unattended condition they always identified the color, and in the divided-attention conditions, participants attended to both word identity and color. Perceptual priming was assessed with perceptual identification and explicit memory with recognition. Relative to the full-attention condition, attending to color always reduced priming. Dividing attention between word identity and color, however, only disrupted priming when these attributes were presented as multiple objects (Experiment 2) but not when they were dimensions of a common object (Experiment 1). On the explicit test, manipulations of attention always affected recognition accuracy.

How big and how close? Habitat patch size and spacing to conserve a threatened species

EPA Science Inventory

We present results of a spatially-explicit, individual-based stochastic dispersal model (HexSim) to evaluate effects of size and spacing of patches of habitat of Northern Spotted Owls (NSO; Strix occidentalis caurina) in Pacific Northwest, USA, to help advise USDI Fish and Wildli...

Interactive Simulations as Implicit Support for Guided-Inquiry

ERIC Educational Resources Information Center

Moore, Emily B.; Herzog, Timothy A.; Perkins, Katherine K.

2013-01-01

We present the results of a study designed to provide insight into interactive simulation use during guided-inquiry activities in chemistry classes. The PhET Interactive Simulations project at the University of Colorado develops interactive simulations that utilize implicit--rather than explicit--scaffolding to support student learning through…

Pronunciation Instruction through Twitter: The Case of Commonly Mispronounced Words

ERIC Educational Resources Information Center

Fouz-González, Jonás

2017-01-01

This paper presents the results of a study aimed at exploring the possibilities Twitter offers for pronunciation instruction. It investigates the potential of a Twitter-based approach based on explicit instruction and input enhancement techniques to help English Foreing Language (EFL) learners improve their pronunciation of segmental and…

Spontaneous Sourcing among Students Reading Multiple Documents

ERIC Educational Resources Information Center

Stromso, Helge I.; Braten, Ivar; Britt, M. Anne; Ferguson, Leila E.

2013-01-01

This study used think-aloud methodology to explore undergraduates' spontaneous attention to and use of source information while reading six documents that presented conflicting views on a controversial social scientific issue in a Google-like environment. Results showed that students explicitly and implicitly paid attention to sources of documents…

Assessing implicit models for nonpolar mean solvation forces: The importance of dispersion and volume terms

PubMed Central

Wagoner, Jason A.; Baker, Nathan A.

2006-01-01

Continuum solvation models provide appealing alternatives to explicit solvent methods because of their ability to reproduce solvation effects while alleviating the need for expensive sampling. Our previous work has demonstrated that Poisson-Boltzmann methods are capable of faithfully reproducing polar explicit solvent forces for dilute protein systems; however, the popular solvent-accessible surface area model was shown to be incapable of accurately describing nonpolar solvation forces at atomic-length scales. Therefore, alternate continuum methods are needed to reproduce nonpolar interactions at the atomic scale. In the present work, we address this issue by supplementing the solvent-accessible surface area model with additional volume and dispersion integral terms suggested by scaled particle models and Weeks–Chandler–Andersen theory, respectively. This more complete nonpolar implicit solvent model shows very good agreement with explicit solvent results and suggests that, although often overlooked, the inclusion of appropriate dispersion and volume terms are essential for an accurate implicit solvent description of atomic-scale nonpolar forces. PMID:16709675

Accurate calculation of conformational free energy differences in explicit water: the confinement-solvation free energy approach.

PubMed

Esque, Jeremy; Cecchini, Marco

2015-04-23

The calculation of the free energy of conformation is key to understanding the function of biomolecules and has attracted significant interest in recent years. Here, we present an improvement of the confinement method that was designed for use in the context of explicit solvent MD simulations. The development involves an additional step in which the solvation free energy of the harmonically restrained conformers is accurately determined by multistage free energy perturbation simulations. As a test-case application, the newly introduced confinement/solvation free energy (CSF) approach was used to compute differences in free energy between conformers of the alanine dipeptide in explicit water. The results are in excellent agreement with reference calculations based on both converged molecular dynamics and umbrella sampling. To illustrate the general applicability of the method, conformational equilibria of met-enkephalin (5 aa) and deca-alanine (10 aa) in solution were also analyzed. In both cases, smoothly converged free-energy results were obtained in agreement with equilibrium sampling or literature calculations. These results demonstrate that the CSF method may provide conformational free-energy differences of biomolecules with small statistical errors (below 0.5 kcal/mol) and at a moderate computational cost even with a full representation of the solvent.

A coarse-grained polarizable force field for the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate

NASA Astrophysics Data System (ADS)

Zeman, Johannes; Uhlig, Frank; Smiatek, Jens; Holm, Christian

2017-12-01

We present a coarse-grained polarizable molecular dynamics force field for the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF6]). For the treatment of electronic polarizability, we employ the Drude model. Our results show that the new explicitly polarizable force field reproduces important static and dynamic properties such as mass density, enthalpy of vaporization, diffusion coefficients, or electrical conductivity in the relevant temperature range. In situations where an explicit treatment of electronic polarizability might be crucial, we expect the force field to be an improvement over non-polarizable models, while still profiting from the reduction of computational cost due to the coarse-grained representation.

Entropic multi-relaxation free-energy lattice Boltzmann model for two-phase flows

NASA Astrophysics Data System (ADS)

Bösch, F.; Dorschner, B.; Karlin, I.

2018-04-01

The entropic multi-relaxation lattice Boltzmann method is extended to two-phase systems following the free-energy approach. Gain in stability is achieved by incorporating the force term due to Korteweg's stress into the redefined entropic stabilizer, which allows simulation of higher Weber and Reynolds numbers with an efficient and explicit algorithm. Results for head-on droplet collisions and droplet impact on super-hydrophobic substrates are matching experimental data accurately. Furthermore, it is demonstrated that the entropic stabilization leads to smaller spurious currents without affecting the interface thickness. The present findings demonstrate the universality of the simple and explicit entropic lattice Boltzmann models and provide a viable and robust alternative to existing methods.

An improved flux-split algorithm applied to hypersonic flows in chemical equilibrium

NASA Technical Reports Server (NTRS)

Palmer, Grant

1988-01-01

An explicit, finite-difference, shock-capturing numerical algorithm is presented and applied to hypersonic flows assumed to be in thermochemical equilibrium. Real-gas chemistry is either loosely coupled to the gasdynamics by way of a Gibbs free energy minimization package or fully coupled using species mass conservation equations with finite-rate chemical reactions. A scheme is developed that maintains stability in the explicit, finite-rate formulation while allowing relatively high time steps. The codes use flux vector splitting to difference the inviscid fluxes and employ real-gas corrections to viscosity and thermal conductivity. Numerical results are compared against existing ballistic range and flight data. Flows about complex geometries are also computed.

Some rules for polydimensional squeezing

NASA Technical Reports Server (NTRS)

Manko, Vladimir I.

1994-01-01

The review of the following results is presented: For mixed state light of N-mode electromagnetic field described by Wigner function which has generic Gaussian form, the photon distribution function is obtained and expressed explicitly in terms of Hermite polynomials of 2N-variables. The momenta of this distribution are calculated and expressed as functions of matrix invariants of the dispersion matrix. The role of new uncertainty relation depending on photon state mixing parameter is elucidated. New sum rules for Hermite polynomials of several variables are found. The photon statistics of polymode even and odd coherent light and squeezed polymode Schroedinger cat light is given explicitly. Photon distribution for polymode squeezed number states expressed in terms of multivariable Hermite polynomials is discussed.

Explicit and exact nontraveling wave solutions of the (3+1)-dimensional potential Yu-Toda-Sasa-Fukuyama equation

NASA Astrophysics Data System (ADS)

Yuan, Na

2018-04-01

With the aid of the symbolic computation, we present an improved ( G ‧ / G ) -expansion method, which can be applied to seek more types of exact solutions for certain nonlinear evolution equations. In illustration, we choose the (3 + 1)-dimensional potential Yu-Toda-Sasa-Fukuyama equation to demonstrate the validity and advantages of the method. As a result, abundant explicit and exact nontraveling wave solutions are obtained including two solitary waves solutions, nontraveling wave solutions and dromion soliton solutions. Some particular localized excitations and the interactions between two solitary waves are researched. The method can be also applied to other nonlinear partial differential equations.

Implicit Attitudes toward the Self Over Time in Chinese Undergraduates

PubMed Central

Yang, Qing; Zhao, Yufang; Guan, Lili; Huang, Xiting

2017-01-01

Although the explicit attitudes of Chinese people toward the self over time are known (i.e., past = present < future), little is known about their implicit attitudes. Two studies were conducted to measure the implicit subjective temporal trajectory (STT) of Chinese undergraduates. Study 1 used a Go/No-go association task to measure participants’ implicit attitudes toward their past, present, and future selves. The obtained implicit STT was different from the explicit pattern found in former research. It showed that the future self was viewed to be identical to the present self and participants implicitly evaluated their present self as better than the past self. Since this comparison of the past and present selves suggested a cultural difference, we aimed to replicate this finding in Study 2. Using an implicit association test, we again found that the present self was more easily associated with positive valence than the past self. Overall, both studies reveal an implicitly inclining-flat STT (i.e., past < present = future) for Chinese undergraduates. Implications of this difference in explicit-implicit measures and the cultural differences of temporal self appraisals are discussed. PMID:29163291

Prediction of Complex Aerodynamic Flows with Explicit Algebraic Stress Models

NASA Technical Reports Server (NTRS)

Abid, Ridha; Morrison, Joseph H.; Gatski, Thomas B.; Speziale, Charles G.

1996-01-01

An explicit algebraic stress equation, developed by Gatski and Speziale, is used in the framework of K-epsilon formulation to predict complex aerodynamic turbulent flows. The nonequilibrium effects are modeled through coefficients that depend nonlinearly on both rotational and irrotational strains. The proposed model was implemented in the ISAAC Navier-Stokes code. Comparisons with the experimental data are presented which clearly demonstrate that explicit algebraic stress models can predict the correct response to nonequilibrium flow.

The key to success in elite athletes? Explicit and implicit motor learning in youth elite and non-elite soccer players.

PubMed

Verburgh, L; Scherder, E J A; van Lange, P A M; Oosterlaan, J

2016-09-01

In sports, fast and accurate execution of movements is required. It has been shown that implicitly learned movements might be less vulnerable than explicitly learned movements to stressful and fast changing circumstances that exist at the elite sports level. The present study provides insight in explicit and implicit motor learning in youth soccer players with different expertise levels. Twenty-seven youth elite soccer players and 25 non-elite soccer players (aged 10-12) performed a serial reaction time task (SRTT). In the SRTT, one of the sequences must be learned explicitly, the other was implicitly learned. No main effect of group was found for implicit and explicit learning on mean reaction time (MRT) and accuracy. However, for MRT, an interaction was found between learning condition, learning phase and group. Analyses showed no group effects for the explicit learning condition, but youth elite soccer players showed better learning in the implicit learning condition. In particular, during implicit motor learning youth elite soccer showed faster MRTs in the early learning phase and earlier reached asymptote performance in terms of MRT. Present findings may be important for sports because children with superior implicit learning abilities in early learning phases may be able to learn more (durable) motor skills in a shorter time period as compared to other children.

Preserved semantic priming effect in alexia.

PubMed

Mimura, M; Goodglass, H; Milberg, W

1996-09-01

BH, a left-handed patient with alexia and nonfluent aphasia, was presented with a lexical-decision task in which words and pronounceable pseudowords were preceded by semantically related or unrelated picture primes (Experiment 1). In Experiment 2, BH was given an explicit reading task using the word lists from Experiment 1. Performance on Experiment 2 disclosed severe reading deficits in both oral reading and semantic matching of the words to pictures. However, in Experiment 1, BH demonstrated a significant semantic priming effect, responding more accurately and more quickly to words preceded by related primes than by unrelated primes. The present results suggest that even in a patient with severe alexia, implicit access to semantic information can be preserved in the absence of explicit identification. The possibility of categorical gradient in implicit activation (living vs. nonliving) in BH was also discussed, which, however, needs to be clarified in the further investigation.

A Knowledge Navigation Method for the Domain of Customers' Services of Mobile Communication Corporations in China

NASA Astrophysics Data System (ADS)

Wu, Jiangning; Wang, Xiaohuan

Rapidly increasing amount of mobile phone users and types of services leads to a great accumulation of complaining information. How to use this information to enhance the quality of customers' services is a big issue at present. To handle this kind of problem, the paper presents an approach to construct a domain knowledge map for navigating the explicit and tacit knowledge in two ways: building the Topic Map-based explicit knowledge navigation model, which includes domain TM construction, a semantic topic expansion algorithm and VSM-based similarity calculation; building Social Network Analysis-based tacit knowledge navigation model, which includes a multi-relational expert navigation algorithm and the criterions to evaluate the performance of expert networks. In doing so, both the customer managers and operators in call centers can find the appropriate knowledge and experts quickly and exactly. The experimental results show that the above method is very powerful for knowledge navigation.

Effect of the magnetic field on coexisting stimulated Raman and Brillouin backscattering of an extraordinary mode

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

Vyas, Ashish, E-mail: ashishvyas.optics@gmail.com; Singh, Ram Kishor, E-mail: ram007kishor@gmail.com; Sharma, R. P., E-mail: rpsharma@ces.iitd.ernet.in

2016-01-15

This paper presents a model to study the interplay between the stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) in the presence of background magnetic field. This formalism is applicable to laser produced plasma as well as to heating mechanism in toroidal system by an extraordinary electromagnetic wave. In the former case, the magnetic field is self-generated, while in the latter case (toroidal plasmas) magnetic field is applied externally. The behavior of one scattering process is explicitly dependent on the coexisting scattering process as well as on the magnetic field. Explicit expressions for the back-reflectivity of scattered beams (SRSmore » and SBS) are presented. It has been demonstrated that due to the magnetic field and coexistence of the scattering processes (SRS and SBS) the back-reflectivity gets modified significantly. Results are also compared with the three wave interaction case (isolated SRS or SBS case)« less

Perceiving age and gender in unfamiliar faces: brain potential evidence for implicit and explicit person categorization.

PubMed

Wiese, Holger; Schweinberger, Stefan R; Neumann, Markus F

2008-11-01

We used repetition priming to investigate implicit and explicit processes of unfamiliar face categorization. During prime and test phases, participants categorized unfamiliar faces according to either age or gender. Faces presented at test were either new or primed in a task-congruent (same task during priming and test) or incongruent (different tasks) condition. During age categorization, reaction times revealed significant priming for both priming conditions, and event-related potentials yielded an increased N170 over the left hemisphere as a result of priming. During gender categorization, congruent faces elicited priming and a latency decrease in the right N170. Accordingly, information about age is extracted irrespective of processing demands, and priming facilitates the extraction of feature information reflected in the left N170 effect. By contrast, priming of gender categorization may depend on whether the task at initial presentation requires configural processing.

Memory biases in remitted depression: the role of negative cognitions at explicit and automatic processing levels.

PubMed

Romero, Nuria; Sanchez, Alvaro; Vazquez, Carmelo

2014-03-01

Cognitive models propose that depression is caused by dysfunctional schemas that endure beyond the depressive episode, representing vulnerability factors for recurrence. However, research testing negative cognitions linked to dysfunctional schemas in formerly depressed individuals is still scarce. Furthermore, negative cognitions are presumed to be linked to biases in recalling negative self-referent information in formerly depressed individuals, but no studies have directly tested this association. In the present study, we evaluated differences between formerly and never-depressed individuals in several experimental indices of negative cognitions and their associations with the recall of emotional self-referent material. Formerly (n = 30) and never depressed individuals (n = 40) completed measures of explicit (i.e., scrambled sentence test) and automatic (i.e., lexical decision task) processing to evaluate negative cognitions. Furthermore participants completed a self-referent incidental recall task to evaluate memory biases. Formerly compared to never depressed individuals showed greater negative cognitions at both explicit and automatic levels of processing. Results also showed greater recall of negative self-referent information in formerly compared to never-depressed individuals. Finally, individual differences in negative cognitions at both explicit and automatic levels of processing predicted greater recall of negative self-referent material in formerly depressed individuals. Analyses of the relationship between explicit and automatic processing indices and memory biases were correlational and the majority of participants in both groups were women. Our findings provide evidence of negative cognitions in formerly depressed individuals at both automatic and explicit levels of processing that may confer a cognitive vulnerability to depression. Copyright © 2013 Elsevier Ltd. All rights reserved.

The universal and automatic association between brightness and positivity.

PubMed

Specker, Eva; Leder, Helmut; Rosenberg, Raphael; Hegelmaier, Lisa Mira; Brinkmann, Hanna; Mikuni, Jan; Kawabata, Hideaki

2018-05-01

The present study investigates the hypothesis that brightness of colors is associated with positivity, postulating that this is an automatic and universal effect. The Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) was used in all studies. Study 1 used color patches varying on brightness, Study 2 used achromatic stimuli to eliminate the potential confounding effects of hue and saturation. Study 3 replicated Study 2 in a different cultural context (Japan vs. Austria), both studies also included a measure of explicit association. All studies confirmed the hypothesis that brightness is associated with positivity, at a significance level of p < .001 and Cohen's D varying from 0.90 to 3.99. Study 1-3 provided support for the notion that this is an automatic effect. Additionally, Study 2 and Study 3 showed that people also have an explicit association of brightness with positivity. However, as expected, our results also show that the implicit association was stronger than the explicit association. Study 3 shows clear support for the universality of our effects. In sum, our results support the idea that brightness is associated with positivity and that these associations are automatic and universal. Copyright © 2018 Elsevier B.V. All rights reserved.

Repetition Suppression and Multi-Voxel Pattern Similarity Differentially Track Implicit and Explicit Visual Memory

PubMed Central

Chun, Marvin M.; Kuhl, Brice A.

2013-01-01

Repeated exposure to a visual stimulus is associated with corresponding reductions in neural activity, particularly within visual cortical areas. It has been argued that this phenomenon of repetition suppression is related to increases in processing fluency or implicit memory. However, repetition of a visual stimulus can also be considered in terms of the similarity of the pattern of neural activity elicited at each exposure—a measure that has recently been linked to explicit memory. Despite the popularity of each of these measures, direct comparisons between the two have been limited, and the extent to which they differentially (or similarly) relate to behavioral measures of memory has not been clearly established. In the present study, we compared repetition suppression and pattern similarity as predictors of both implicit and explicit memory. Using functional magnetic resonance imaging, we scanned 20 participants while they viewed and categorized repeated presentations of scenes. Repetition priming (facilitated categorization across repetitions) was used as a measure of implicit memory, and subsequent scene recognition was used as a measure of explicit memory. We found that repetition priming was predicted by repetition suppression in prefrontal, parietal, and occipitotemporal regions; however, repetition priming was not predicted by pattern similarity. In contrast, subsequent explicit memory was predicted by pattern similarity (across repetitions) in some of the same occipitotemporal regions that exhibited a relationship between priming and repetition suppression; however, explicit memory was not related to repetition suppression. This striking double dissociation indicates that repetition suppression and pattern similarity differentially track implicit and explicit learning. PMID:24027275

Sleep benefits in parallel implicit and explicit measures of episodic memory.

PubMed

Weber, Frederik D; Wang, Jing-Yi; Born, Jan; Inostroza, Marion

2014-03-14

Research in rats using preferences during exploration as a measure of memory has indicated that sleep is important for the consolidation of episodic-like memory, i.e., memory for an event bound into specific spatio-temporal context. How these findings relate to human episodic memory is unclear. We used spontaneous preferences during visual exploration and verbal recall as, respectively, implicit and explicit measures of memory, to study effects of sleep on episodic memory consolidation in humans. During encoding before 10-h retention intervals that covered nighttime sleep or daytime wakefulness, two groups of young adults were presented with two episodes that were 1-h apart. Each episode entailed a spatial configuration of four different faces in a 3 × 3 grid of locations. After the retention interval, implicit spatio-temporal recall performance was assessed by eye-tracking visual exploration of another configuration of four faces of which two were from the first and second episode, respectively; of the two faces one was presented at the same location as during encoding and the other at another location. Afterward explicit verbal recall was assessed. Measures of implicit and explicit episodic memory retention were positively correlated (r = 0.57, P < 0.01), and were both better after nighttime sleep than daytime wakefulness (P < 0.05). In the sleep group, implicit episodic memory recall was associated with increased fast spindles during nonrapid eye movement (NonREM) sleep (r = 0.62, P < 0.05). Together with concordant observations in rats our results indicate that consolidation of genuinely episodic memory benefits from sleep.

Sleep benefits in parallel implicit and explicit measures of episodic memory

PubMed Central

Weber, Frederik D.; Wang, Jing-Yi; Born, Jan; Inostroza, Marion

2014-01-01

Research in rats using preferences during exploration as a measure of memory has indicated that sleep is important for the consolidation of episodic-like memory, i.e., memory for an event bound into specific spatio-temporal context. How these findings relate to human episodic memory is unclear. We used spontaneous preferences during visual exploration and verbal recall as, respectively, implicit and explicit measures of memory, to study effects of sleep on episodic memory consolidation in humans. During encoding before 10-h retention intervals that covered nighttime sleep or daytime wakefulness, two groups of young adults were presented with two episodes that were 1-h apart. Each episode entailed a spatial configuration of four different faces in a 3 × 3 grid of locations. After the retention interval, implicit spatio-temporal recall performance was assessed by eye-tracking visual exploration of another configuration of four faces of which two were from the first and second episode, respectively; of the two faces one was presented at the same location as during encoding and the other at another location. Afterward explicit verbal recall was assessed. Measures of implicit and explicit episodic memory retention were positively correlated (r = 0.57, P < 0.01), and were both better after nighttime sleep than daytime wakefulness (P < 0.05). In the sleep group, implicit episodic memory recall was associated with increased fast spindles during nonrapid eye movement (NonREM) sleep (r = 0.62, P < 0.05). Together with concordant observations in rats our results indicate that consolidation of genuinely episodic memory benefits from sleep. PMID:24634354

The Underestimated Significance of Conditioning in Placebo Hypoalgesia and Nocebo Hyperalgesia

PubMed Central

Witthöft, Michael

2018-01-01

Placebo and nocebo effects are intriguing phenomena in pain perception with important implications for clinical research and practice because they can alleviate or increase pain. According to current theoretical accounts, these effects can be shaped by verbal suggestions, social observational learning, and classical conditioning and are necessarily mediated by explicit expectation. In this review, we focus on the contribution of conditioning in the induction of placebo hypoalgesia and nocebo hyperalgesia and present accumulating evidence that conditioning independent from explicit expectation can cause these effects. Especially studies using subliminal stimulus presentation and implicit conditioning (i.e., without contingency awareness) that bypass the development of explicit expectation suggest that conditioning without explicit expectation can lead to placebo and nocebo effects in pain perception. Because only few studies have investigated clinical samples, the picture seems less clear when it comes to patient populations with chronic pain. However, conditioning appears to be a promising means to optimize treatment. In order to get a better insight into the mechanisms of placebo and nocebo effects in pain and the possible benefits of conditioning compared to explicit expectation, future studies should carefully distinguish both methods of induction. PMID:29670678

Assessment of the Simulated Molecular Composition with the GECKO-A Modeling Tool Using Chamber Observations for α-Pinene.

NASA Astrophysics Data System (ADS)

Aumont, B.; Camredon, M.; Isaacman-VanWertz, G. A.; Karam, C.; Valorso, R.; Madronich, S.; Kroll, J. H.

2016-12-01

Gas phase oxidation of VOC is a gradual process leading to the formation of multifunctional organic compounds, i.e., typically species with higher oxidation state, high water solubility and low volatility. These species contribute to the formation of secondary organic aerosols (SOA) viamultiphase processes involving a myriad of organic species that evolve through thousands of reactions and gas/particle mass exchanges. Explicit chemical mechanisms reflect the understanding of these multigenerational oxidation steps. These mechanisms rely directly on elementary reactions to describe the chemical evolution and track the identity of organic carbon through various phases down to ultimate oxidation products. The development, assessment and improvement of such explicit schemes is a key issue, as major uncertainties remain on the chemical pathways involved during atmospheric oxidation of organic matter. An array of mass spectrometric techniques (CIMS, PTRMS, AMS) was recently used to track the composition of organic species during α-pinene oxidation in the MIT environmental chamber, providing an experimental database to evaluate and improve explicit mechanisms. In this study, the GECKO-A tool (Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere) is used to generate fully explicit oxidation schemes for α-pinene multiphase oxidation simulating the MIT experiment. The ability of the GECKO-A chemical scheme to explain the organic molecular composition in the gas and the condensed phases is explored. First results of this model/observation comparison at the molecular level will be presented.

Activity-Centered Domain Characterization for Problem-Driven Scientific Visualization

PubMed Central

Marai, G. Elisabeta

2018-01-01

Although visualization design models exist in the literature in the form of higher-level methodological frameworks, these models do not present a clear methodological prescription for the domain characterization step. This work presents a framework and end-to-end model for requirements engineering in problem-driven visualization application design. The framework and model are based on the activity-centered design paradigm, which is an enhancement of human-centered design. The proposed activity-centered approach focuses on user tasks and activities, and allows an explicit link between the requirements engineering process with the abstraction stage—and its evaluation—of existing, higher-level visualization design models. In a departure from existing visualization design models, the resulting model: assigns value to a visualization based on user activities; ranks user tasks before the user data; partitions requirements in activity-related capabilities and nonfunctional characteristics and constraints; and explicitly incorporates the user workflows into the requirements process. A further merit of this model is its explicit integration of functional specifications, a concept this work adapts from the software engineering literature, into the visualization design nested model. A quantitative evaluation using two sets of interdisciplinary projects supports the merits of the activity-centered model. The result is a practical roadmap to the domain characterization step of visualization design for problem-driven data visualization. Following this domain characterization model can help remove a number of pitfalls that have been identified multiple times in the visualization design literature. PMID:28866550

Explicit and implicit processes in behavioural adaptation to road width.

PubMed

Lewis-Evans, Ben; Charlton, Samuel G

2006-05-01

The finding that drivers may react to safety interventions in a way that is contrary to what was intended is the phenomenon of behavioural adaptation. This phenomenon has been demonstrated across various safety interventions and has serious implications for road safety programs the world over. The present research used a driving simulator to assess behavioural adaptation in drivers' speed and lateral displacement in response to manipulations of road width. Of interest was whether behavioural adaptation would occur and whether we could determine whether it was the result of explicit, conscious decisions or implicit perceptual processes. The results supported an implicit, zero perceived risk model of behavioural adaptation with reduced speeds on a narrowed road accompanied by increased ratings of risk and a marked inability of the participants to identify that any change in road width had occurred.

A hybridized method for computing high-Reynolds-number hypersonic flow about blunt bodies

NASA Technical Reports Server (NTRS)

Weilmuenster, K. J.; Hamilton, H. H., II

1979-01-01

A hybridized method for computing the flow about blunt bodies is presented. In this method the flow field is split into its viscid and inviscid parts. The forebody flow field about a parabolic body is computed. For the viscous solution, the Navier-Stokes equations are solved on orthogonal parabolic coordinates using explicit finite differencing. The inviscid flow is determined by using a Moretti type scheme in which the Euler equations are solved, using explicit finite differences, on a nonorthogonal coordinate system which uses the bow shock as an outer boundary. The two solutions are coupled along a common data line and are marched together in time until a converged solution is obtained. Computed results, when compared with experimental and analytical results, indicate the method works well over a wide range of Reynolds numbers and Mach numbers.

Does attitude acquisition in evaluative conditioning without explicit CS-US memory reflect implicit misattribution of affect?

PubMed

Mierop, Adrien; Hütter, Mandy; Stahl, Christoph; Corneille, Olivier

2018-02-05

Research that dissociates different types of processes within a given task using a processing tree approach suggests that attitudes may be acquired through evaluative conditioning in the absence of explicit encoding of CS-US pairings in memory. This research distinguishes explicit memory for the CS-US pairings from CS-liking acquired without encoding of CS-US pairs in explicit memory. It has been suggested that the latter effect may be due to an implicit misattribution process that is assumed to operate when US evocativeness is low. In the present research, the latter assumption was supported neither by two high-powered experiments nor by complementary meta-analytic evidence, whereas evocativeness exerted an influence on explicit memory. This pattern of findings is inconsistent with the view that CS-liking acquired without encoding of CS-US pairs in explicit memory reflects an implicit misattribution process at learning. Hence, the underlying learning process is awaiting further empirical scrutiny.

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.

Implicit and Explicit Attention to Pictures and Words: An fMRI-Study of Concurrent Emotional Stimulus Processing.

PubMed

Flaisch, Tobias; Imhof, Martin; Schmälzle, Ralf; Wentz, Klaus-Ulrich; Ibach, Bernd; Schupp, Harald T

2015-01-01

The present study utilized functional magnetic resonance imaging (fMRI) to examine the neural processing of concurrently presented emotional stimuli under varying explicit and implicit attention demands. Specifically, in separate trials, participants indicated the category of either pictures or words. The words were placed over the center of the pictures and the picture-word compound-stimuli were presented for 1500 ms in a rapid event-related design. The results reveal pronounced main effects of task and emotion: the picture categorization task prompted strong activations in visual, parietal, temporal, frontal, and subcortical regions; the word categorization task evoked increased activation only in left extrastriate cortex. Furthermore, beyond replicating key findings regarding emotional picture and word processing, the results point to a dissociation of semantic-affective and sensory-perceptual processes for words: while emotional words engaged semantic-affective networks of the left hemisphere regardless of task, the increased activity in left extrastriate cortex associated with explicitly attending to words was diminished when the word was overlaid over an erotic image. Finally, we observed a significant interaction between Picture Category and Task within dorsal visual-associative regions, inferior parietal, and dorsolateral, and medial prefrontal cortices: during the word categorization task, activation was increased in these regions when the words were overlaid over erotic as compared to romantic pictures. During the picture categorization task, activity in these areas was relatively decreased when categorizing erotic as compared to romantic pictures. Thus, the emotional intensity of the pictures strongly affected brain regions devoted to the control of task-related word or picture processing. These findings are discussed with respect to the interplay of obligatory stimulus processing with task-related attentional control mechanisms.

Implicit and Explicit Attention to Pictures and Words: An fMRI-Study of Concurrent Emotional Stimulus Processing

PubMed Central

Flaisch, Tobias; Imhof, Martin; Schmälzle, Ralf; Wentz, Klaus-Ulrich; Ibach, Bernd; Schupp, Harald T.

2015-01-01

The present study utilized functional magnetic resonance imaging (fMRI) to examine the neural processing of concurrently presented emotional stimuli under varying explicit and implicit attention demands. Specifically, in separate trials, participants indicated the category of either pictures or words. The words were placed over the center of the pictures and the picture-word compound-stimuli were presented for 1500 ms in a rapid event-related design. The results reveal pronounced main effects of task and emotion: the picture categorization task prompted strong activations in visual, parietal, temporal, frontal, and subcortical regions; the word categorization task evoked increased activation only in left extrastriate cortex. Furthermore, beyond replicating key findings regarding emotional picture and word processing, the results point to a dissociation of semantic-affective and sensory-perceptual processes for words: while emotional words engaged semantic-affective networks of the left hemisphere regardless of task, the increased activity in left extrastriate cortex associated with explicitly attending to words was diminished when the word was overlaid over an erotic image. Finally, we observed a significant interaction between Picture Category and Task within dorsal visual-associative regions, inferior parietal, and dorsolateral, and medial prefrontal cortices: during the word categorization task, activation was increased in these regions when the words were overlaid over erotic as compared to romantic pictures. During the picture categorization task, activity in these areas was relatively decreased when categorizing erotic as compared to romantic pictures. Thus, the emotional intensity of the pictures strongly affected brain regions devoted to the control of task-related word or picture processing. These findings are discussed with respect to the interplay of obligatory stimulus processing with task-related attentional control mechanisms. PMID:26733895

Analytical energy gradients for explicitly correlated wave functions. I. Explicitly correlated second-order Møller-Plesset perturbation theory

NASA Astrophysics Data System (ADS)

Győrffy, Werner; Knizia, Gerald; Werner, Hans-Joachim

2017-12-01

We present the theory and algorithms for computing analytical energy gradients for explicitly correlated second-order Møller-Plesset perturbation theory (MP2-F12). The main difficulty in F12 gradient theory arises from the large number of two-electron integrals for which effective two-body density matrices and integral derivatives need to be calculated. For efficiency, the density fitting approximation is used for evaluating all two-electron integrals and their derivatives. The accuracies of various previously proposed MP2-F12 approximations [3C, 3C(HY1), 3*C(HY1), and 3*A] are demonstrated by computing equilibrium geometries for a set of molecules containing first- and second-row elements, using double-ζ to quintuple-ζ basis sets. Generally, the convergence of the bond lengths and angles with respect to the basis set size is strongly improved by the F12 treatment, and augmented triple-ζ basis sets are sufficient to closely approach the basis set limit. The results obtained with the different approximations differ only very slightly. This paper is the first step towards analytical gradients for coupled-cluster singles and doubles with perturbative treatment of triple excitations, which will be presented in the second part of this series.

Explicit expressions for meromorphic solutions of autonomous nonlinear ordinary differential equations

NASA Astrophysics Data System (ADS)

Demina, Maria V.; Kudryashov, Nikolay A.

2011-03-01

Meromorphic solutions of autonomous nonlinear ordinary differential equations are studied. An algorithm for constructing meromorphic solutions in explicit form is presented. General expressions for meromorphic solutions (including rational, periodic, elliptic) are found for a wide class of autonomous nonlinear ordinary differential equations.

Goal-oriented training affects decision-making processes in virtual and simulated fire and rescue environments.

PubMed

Cohen-Hatton, Sabrina R; Honey, R C

2015-12-01

Decisions made by operational commanders at emergency incidents have been characterized as involving a period of information gathering followed by courses of action that are often generated without explicit plan formulation. We examined the efficacy of goal-oriented training in engendering explicit planning that would enable better communication at emergency incidents. While standard training mirrored current operational guidance, goal-oriented training incorporated "decision controls" that highlighted the importance of evaluating goals, anticipated consequences, and risk/benefit analyses once a potential course of action has been identified. In Experiment 1, 3 scenarios (a house fire, road traffic collision, and skip fire) were presented in a virtual environment, and in Experiment 2 they were recreated on the fireground. In Experiment 3, the house fire was recreated as a "live burn," and incident commanders and their crews responded to this scenario as an emergency incident. In all experiments, groups given standard training showed the reported tendency to move directly from information gathering to action, whereas those given goal-oriented training were more likely to develop explicit plans and show anticipatory situational awareness. These results indicate that training can be readily modified to promote explicit plan formulation that could facilitate plan sharing between incident commanders and their teams. (c) 2015 APA, all rights reserved).

(In)Congruence of implicit and explicit communal motives predicts the quality and stability of couple relationships.

PubMed

Hagemeyer, Birk; Neberich, Wiebke; Asendorpf, Jens B; Neyer, Franz J

2013-08-01

Previous research has shown that motive congruence, as observed in convergingly high or low scores on implicit and explicit motive measures, promotes well-being and health. Extending this individual perspective to the realm of couple relationships, the present investigation examined intra- and interpersonal effects of communal motive (in)congruence on relationship satisfaction and stability. The implicit partner-related need for communion, the explicit desire for closeness, and relationship satisfaction were assessed in a sample of 547 heterosexual couples aged 18 to 73 years. In a one-year follow-up study, information on relationship stability was obtained, and relationship satisfaction was reassessed. The researchers tested cross-sectional and longitudinal effects of motive (in)congruence by dyadic moderation analyses. Individuals scoring congruently high on both motives reported the highest relationship satisfaction in concurrence with motive assessment and 1 year later. In addition, motive incongruence predicted an increased risk of relationship breakup over 1 year. The results highlight the significance of both implicit and explicit motives for couple relationships. Motive incongruence was confirmed as a dispositional risk factor that so far has not been considered in couple research. Future research directions addressing potential mediators of the observed effects and potential moderators of motive (in)congruence are discussed. © 2012 Wiley Periodicals, Inc.

The development of an explicit thermochemical nonequilibrium algorithm and its application to compute three dimensional AFE flowfields

NASA Technical Reports Server (NTRS)

Palmer, Grant

1989-01-01

This study presents a three-dimensional explicit, finite-difference, shock-capturing numerical algorithm applied to viscous hypersonic flows in thermochemical nonequilibrium. The algorithm employs a two-temperature physical model. Equations governing the finite-rate chemical reactions are fully-coupled to the gas dynamic equations using a novel coupling technique. The new coupling method maintains stability in the explicit, finite-rate formulation while allowing relatively large global time steps. The code uses flux-vector accuracy. Comparisons with experimental data and other numerical computations verify the accuracy of the present method. The code is used to compute the three-dimensional flowfield over the Aeroassist Flight Experiment (AFE) vehicle at one of its trajectory points.

Now You See It, Now You Don't: Repetition Blindness for Nonwords

ERIC Educational Resources Information Center

Morris, Alison L.; Still, Mary L.

2008-01-01

Repetition blindness (RB) for nonwords has been found in some studies, but not in others. The authors propose that the discrepancy in results is fueled by participant strategy; specifically, when rapid serial visual presentation lists are short and participants are explicitly informed that some trials will contain repetitions, participants are…

Recognition of Famous Names in Psychology by Students and Staff.

ERIC Educational Resources Information Center

Bunnell, Julie K.

1992-01-01

Presents results of a name recognition questionnaire testing the historical awareness of psychology majors and faculty members. Reports that students showed a low level of name recognition prior to taking a course in the history of psychology. Concludes that explicit instruction is required to impart knowledge of the history of the discipline. (DK)

Controllability in nonlinear systems

NASA Technical Reports Server (NTRS)

Hirschorn, R. M.

1975-01-01

An explicit expression for the reachable set is obtained for a class of nonlinear systems. This class is described by a chain condition on the Lie algebra of vector fields associated with each nonlinear system. These ideas are used to obtain a generalization of a controllability result for linear systems in the case where multiplicative controls are present.

Landscape ecology: Past, present, and future [Chapter 4

Treesearch

Samuel A. Cushman; Jeffrey S. Evans; Kevin McGarigal

2010-01-01

In the preceding chapters we discussed the central role that spatial and temporal variability play in ecological systems, the importance of addressing these explicitly within ecological analyses and the resulting need to carefully consider spatial and temporal scale and scaling. Landscape ecology is the science of linking patterns and processes across scale in both...

Insight into the Chemistry Skills Gap: The Duality between Expected and Desired Skills

ERIC Educational Resources Information Center

Kondo, Anne E.; Fair, Justin D.

2017-01-01

Results from an employer survey that examines the skills gap that exists for students majoring in chemistry are presented. Employers expect candidates with technical abilities but desire those who possess strong interprofessional skills. Although employers do not expect students to have had explicit teaching and application of interprofessional…

Alternative Form of the Hydrogenic Wave Functions for an Extended, Uniformly Charged Nucleus.

ERIC Educational Resources Information Center

Ley-Koo, E.; And Others

1980-01-01

Presented are forms of harmonic oscillator attraction and Coulomb wave functions which can be explicitly constructed and which lead to numerical results for the energy eigenvalues and eigenfunctions of the atomic system. The Schrodinger equation and its solution and specific cases of muonic atoms illustrating numerical calculations are included.…

The hierarchical nature of the spin alignment of dark matter haloes in filaments

NASA Astrophysics Data System (ADS)

Aragon-Calvo, M. A.; Yang, Lin Forrest

2014-05-01

Dark matter haloes in cosmological filaments and walls have (in average) their spin vector aligned with their host structure. While haloes in walls are aligned with the plane of the wall independently of their mass, haloes in filaments present a mass-dependent two-regime orientation. Here, we show that the transition mass determining the change in the alignment regime (from parallel to perpendicular) depends on the hierarchical level in which the halo is located, reflecting the hierarchical nature of the Cosmic Web. By explicitly exposing the hierarchical structure of the Cosmic Web, we are able to identify the contributions of different components of the filament network to the alignment signal. We propose a unifying picture of angular momentum acquisition that is based on the results presented here and previous results found by other authors. In order to do a hierarchical characterization of the Cosmic Web, we introduce a new implementation of the multiscale morphology filter, the MMF-2, that significantly improves the identification of structures and explicitly describes their hierarchy. L36

Nonstandard Dirac equations for nonstandard spinors

NASA Astrophysics Data System (ADS)

Nikitin, A. G.

2014-11-01

Generalized Dirac equation with operator mass term is presented. Its solutions are nonstandard spinors (NSS) which, like eigenspinoren des Ladungskonjugationsoperators (ELKO), are eigenvectors of the charge conjugation and dual-helicity operators. It is demonstrated that in spite of their noncovariant nature the NSS can serve as a carrier space of a representation of Poincaré group. However, the corresponding boost generators are not manifestly covariant and generate nonlocal momentum dependent transformations, which are presented explicitly. These results can present a new look on group-theoretical grounds of ELKO theories.

Characteristics of implicit chaining in cotton-top tamarins (Saguinus oedipus).

PubMed

Locurto, Charles; Gagne, Matthew; Nutile, Lauren

2010-07-01

In human cognition there has been considerable interest in observing the conditions under which subjects learn material without explicit instructions to learn. In the present experiments, we adapted this issue to nonhumans by asking what subjects learn in the absence of explicit reinforcement for correct responses. Two experiments examined the acquisition of sequence information by cotton-top tamarins (Saguinus oedipus) when such learning was not demanded by the experimental contingencies. An implicit chaining procedure was used in which visual stimuli were presented serially on a touchscreen. Subjects were required to touch one stimulus to advance to the next stimulus. Stimulus presentations followed a pattern, but learning the pattern was not necessary for reinforcement. In Experiment 1 the chain consisted of five different visual stimuli that were presented in the same order on each trial. Each stimulus could occur at any one of six touchscreen positions. In Experiment 2 the same visual element was presented serially in the same five locations on each trial, thereby allowing a behavioral pattern to be correlated with the visual pattern. In this experiment two new tests, a Wild-Card test and a Running-Start test, were used to assess what was learned in this procedure. Results from both experiments indicated that tamarins acquired more information from an implicit chain than was required by the contingencies of reinforcement. These results contribute to the developing literature on nonhuman analogs of implicit learning.

The Role of Explicit Need Strength for Emotions during Learning

ERIC Educational Resources Information Center

Flunger, Barbara; Pretsch, Johanna; Schmitt, Manfred; Ludwig, Peter

2013-01-01

According to self-determination theory, the satisfaction of the basic needs for autonomy, competence, and relatedness influences achievement emotions and situational interest. The present study investigated whether domain-specific explicit need strength moderated the impact of need satisfaction/dissatisfaction on the outcomes achievement emotions…

Effective Reading and Writing Instruction: A Focus on Modeling

ERIC Educational Resources Information Center

Regan, Kelley; Berkeley, Sheri

2012-01-01

When providing effective reading and writing instruction, teachers need to provide explicit modeling. Modeling is particularly important when teaching students to use cognitive learning strategies. Examples of how teachers can provide specific, explicit, and flexible instructional modeling is presented in the context of two evidence-based…

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)…

Effects of reducing attentional resources on implicit and explicit memory after severe traumatic brain injury.

PubMed

Watt, S; Shores, E A; Kinoshita, S

1999-07-01

Implicit and explicit memory were examined in individuals with severe traumatic brain injury (TBI) under conditions of full and divided attention. Participants included 12 individuals with severe TBI and 12 matched controls. In Experiment 1, participants carried out an implicit test of word-stem completion and an explicit test of cued recall. Results demonstrated that TBI participants exhibited impaired explicit memory but preserved implicit memory. In Experiment 2, a significant reduction in the explicit memory performance of both TBI and control participants, as well as a significant decrease in the implicit memory performance of TBI participants, was achieved by reducing attentional resources at encoding. These results indicated that performance on an implicit task of word-stem completion may require the availability of additional attentional resources that are not preserved after severe TBI.

The Distinct Role of the Amygdala, Superior Colliculus and Pulvinar in Processing of Central and Peripheral Snakes

PubMed Central

Almeida, Inês; Soares, Sandra C.; Castelo-Branco, Miguel

2015-01-01

Introduction Visual processing of ecologically relevant stimuli involves a central bias for stimuli demanding detailed processing (e.g., faces), whereas peripheral object processing is based on coarse identification. Fast detection of animal shapes holding a significant phylogenetic value, such as snakes, may benefit from peripheral vision. The amygdala together with the pulvinar and the superior colliculus are implicated in an ongoing debate regarding their role in automatic and deliberate spatial processing of threat signals. Methods Here we tested twenty healthy participants in an fMRI task, and investigated the role of spatial demands (the main effect of central vs. peripheral vision) in the processing of fear-relevant ecological features. We controlled for stimulus dependence using true or false snakes; snake shapes or snake faces and for task constraints (implicit or explicit). The main idea justifying this double task is that amygdala and superior colliculus are involved in both automatic and controlled processes. Moreover the explicit/implicit instruction in the task with respect to emotion is not necessarily equivalent to explicit vs. implicit in the sense of endogenous vs. exogenous attention, or controlled vs. automatic processes. Results We found that stimulus-driven processing led to increased amygdala responses specifically to true snake shapes presented in the centre or in the peripheral left hemifield (right hemisphere). Importantly, the superior colliculus showed significantly biased and explicit central responses to snake-related stimuli. Moreover, the pulvinar, which also contains foveal representations, also showed strong central responses, extending the results of a recent single cell pulvinar study in monkeys. Similar hemispheric specialization was found across structures: increased amygdala responses occurred to true snake shapes presented to the right hemisphere, with this pattern being closely followed by the superior colliculus and the pulvinar. Conclusion These results show that subcortical structures containing foveal representations such as the amygdala, pulvinar and superior colliculus play distinct roles in the central and peripheral processing of snake shapes. Our findings suggest multiple phylogenetic fingerprints in the responses of subcortical structures to fear-relevant stimuli. PMID:26075614

Preserved memory-based orienting of attention with impaired explicit memory in healthy ageing

PubMed Central

Salvato, Gerardo; Patai, Eva Z.; Nobre, Anna C.

2016-01-01

It is increasingly recognised that spatial contextual long-term memory (LTM) prepares neural activity for guiding visuo-spatial attention in a proactive manner. In the current study, we investigated whether the decline in explicit memory observed in healthy ageing would compromise this mechanism. We compared the behavioural performance of younger and older participants on learning new contextual memories, on orienting visual attention based on these learnt contextual associations, and on explicit recall of contextual memories. We found a striking dissociation between older versus younger participants in the relationship between the ability to retrieve contextual memories versus the ability to use these to guide attention to enhance performance on a target-detection task. Older participants showed significant deficits in the explicit retrieval task, but their behavioural benefits from memory-based orienting of attention were equivalent to those in young participants. Furthermore, memory-based orienting correlated significantly with explicit contextual LTM in younger adults but not in older adults. These results suggest that explicit memory deficits in ageing might not compromise initial perception and encoding of events. Importantly, the results also shed light on the mechanisms of memory-guided attention, suggesting that explicit contextual memories are not necessary. PMID:26649914

Implicit memory. Retention without remembering.

PubMed

Roediger, H L

1990-09-01

Explicit measures of human memory, such as recall or recognition, reflect conscious recollection of the past. Implicit tests of retention measure transfer (or priming) from past experience on tasks that do not require conscious recollection of recent experiences for their performance. The article reviews research on the relation between explicit and implicit memory. The evidence points to substantial differences between standard explicit and implicit tests, because many variables create dissociations between these tests. For example, although pictures are remembered better than words on explicit tests, words produce more priming than do pictures on several implicit tests. These dissociations may implicate different memory systems that subserve distinct memorial functions, but the present argument is that many dissociations can be understood by appealing to general principles that apply to both explicit and implicit tests. Phenomena studied under the rubric of implicit memory may have important implications in many other fields, including social cognition, problem solving, and cognitive development.

Explicit and Implicit Emotion Regulation: A Dual-Process Framework

PubMed Central

Gyurak, Anett; Gross, James J.; Etkin, Amit

2012-01-01

It is widely acknowledged that emotions can be regulated in an astonishing variety of ways. Most research to date has focused on explicit (effortful) forms of emotion regulation. However, there is growing research interest in implicit (automatic) forms of emotion regulation. To organize emerging findings, we present a dual-process framework that integrates explicit and implicit forms of emotion regulation, and argue that both forms of regulation are necessary for well-being. In the first section of this review, we provide a broad overview of the construct of emotion regulation, with an emphasis on explicit and implicit processes. In the second section, we focus on explicit emotion regulation, considering both neural mechanisms that are associated with these processes and their experiential and physiological consequences. In the third section, we turn to several forms of implicit emotion regulation, and integrate the burgeoning literature in this area. We conclude by outlining open questions and areas for future research. PMID:21432682

Discrepancies between explicit and implicit self-esteem: implications for mate retention strategies and perceived infidelity.

PubMed

Zeigler-Hill, Virgil; Fulton, Jessica J; McLemore, Chandler

2012-01-01

The purpose of the present study was to examine whether the association between explicit self-esteem and relationship outcomes was moderated by implicit self-esteem. This was accomplished by asking 210 undergraduates who were currently involved in romantic relationships to complete measures of their explicit self-esteem, implicit self-esteem, mate retention strategies, and likelihood of future infidelity. Implicit self-esteem was found to moderate the association between high explicit self-esteem and relationship outcomes for male participants such that men with discrepant high self-esteem (i.e., high explicit self-esteem but low implicit self-esteem) reported less use of mate retention strategies and perceived a greater likelihood of future infidelity in their relationships during the next year. These findings provide additional support for the idea that fragile self-esteem may have consequences for the manner in which individuals perceive their relationships.

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

Dalvit, Diego; Messina, Riccardo; Maia Neto, Paulo

We develop the scattering approach for the dispersive force on a ground state atom on top of a corrugated surface. We present explicit results to first order in the corrugation amplitude. A variety of analytical results are derived in different limiting cases, including the van der Waals and Casimir-Polder regimes. We compute numerically the exact first-order dispersive potential for arbitrary separation distances and corrugation wavelengths, for a Rubidium atom on top of a silicon or gold corrugated surface. We consider in detail the correction to the proximity force approximation, and present a very simple approximation algorithm for computing the potential.

A particle-in-cell method for the simulation of plasmas based on an unconditionally stable field solver

DOE PAGES

Wolf, Eric M.; Causley, Matthew; Christlieb, Andrew; ...

2016-08-09

Here, we propose a new particle-in-cell (PIC) method for the simulation of plasmas based on a recently developed, unconditionally stable solver for the wave equation. This method is not subject to a CFL restriction, limiting the ratio of the time step size to the spatial step size, typical of explicit methods, while maintaining computational cost and code complexity comparable to such explicit schemes. We describe the implementation in one and two dimensions for both electrostatic and electromagnetic cases, and present the results of several standard test problems, showing good agreement with theory with time step sizes much larger than allowedmore » by typical CFL restrictions.« less

Nonlinear truncation error analysis of finite difference schemes for the Euler equations

NASA Technical Reports Server (NTRS)

Klopfer, G. H.; Mcrae, D. S.

1983-01-01

It is pointed out that, in general, dissipative finite difference integration schemes have been found to be quite robust when applied to the Euler equations of gas dynamics. The present investigation considers a modified equation analysis of both implicit and explicit finite difference techniques as applied to the Euler equations. The analysis is used to identify those error terms which contribute most to the observed solution errors. A technique for analytically removing the dominant error terms is demonstrated, resulting in a greatly improved solution for the explicit Lax-Wendroff schemes. It is shown that the nonlinear truncation errors are quite large and distributed quite differently for each of the three conservation equations as applied to a one-dimensional shock tube problem.

Spectral distances on the doubled Moyal plane using Dirac eigenspinors

NASA Astrophysics Data System (ADS)

Kumar, Kaushlendra; Chakraborty, Biswajit

2018-04-01

We present here a novel method for computing spectral distances in the doubled Moyal plane in a noncommutative geometrical framework using Dirac eigenspinors, while solving the Lipschitz ball condition explicitly through matrices. The standard results of longitudinal, transverse, and hypotenuse distances between different pairs of pure states have been computed and the Pythagorean equality between them has been reproduced. The issue of the nonunital nature of the Moyal plane algebra is taken care of through a sequence of projection operators constructed from Dirac eigenspinors, which plays a crucial role throughout this paper. At the end, a toy model for a "Higgs field" has been constructed by fluctuating the Dirac operator and the variation on the transverse distance has been demonstrated, through an explicit computation.

L1 Adaptive Control Augmentation System with Application to the X-29 Lateral/Directional Dynamics: A Multi-Input Multi-Output Approach

NASA Technical Reports Server (NTRS)

Griffin, Brian Joseph; Burken, John J.; Xargay, Enric

2010-01-01

This paper presents an L(sub 1) adaptive control augmentation system design for multi-input multi-output nonlinear systems in the presence of unmatched uncertainties which may exhibit significant cross-coupling effects. A piecewise continuous adaptive law is adopted and extended for applicability to multi-input multi-output systems that explicitly compensates for dynamic cross-coupling. In addition, explicit use of high-fidelity actuator models are added to the L1 architecture to reduce uncertainties in the system. The L(sub 1) multi-input multi-output adaptive control architecture is applied to the X-29 lateral/directional dynamics and results are evaluated against a similar single-input single-output design approach.

Strength of Intentional Effort Enhances the Sense of Agency

PubMed Central

Minohara, Rin; Wen, Wen; Hamasaki, Shunsuke; Maeda, Takaki; Kato, Motoichiro; Yamakawa, Hiroshi; Yamashita, Atsushi; Asama, Hajime

2016-01-01

Sense of agency (SoA) refers to the feeling of controlling one’s own actions, and the experience of controlling external events with one’s actions. The present study examined the effect of strength of intentional effort on SoA. We manipulated the strength of intentional effort using three types of buttons that differed in the amount of force required to depress them. We used a self-attribution task as an explicit measure of SoA. The results indicate that strength of intentional effort enhanced self-attribution when action-effect congruency was unreliable. We concluded that intentional effort importantly affects the integration of multiple cues affecting explicit judgments of agency when the causal relationship action and effect was unreliable. PMID:27536267

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.

Measures for Assessing Student Attitudes toward Older People

ERIC Educational Resources Information Center

Lin, Xiaoping; Bryant, Christina; Boldero, Jennifer

2011-01-01

Measuring medical and allied health students' attitudes towards older people has been identified as an important research area. The present study compared the use of implicit and explicit attitude measures. Sixty-five undergraduates completed one explicit measure, the Fraboni Scale of Ageism (FSA), (Fraboni, Saltstone, & Hughes, 1990) and one…

Teaching Spoken Discourse Markers Explicitly: A Comparison of III and PPP

ERIC Educational Resources Information Center

Jones, Christian; Carter, Ronald

2014-01-01

This article reports on mixed methods classroom research carried out at a British university. The study investigates the effectiveness of two different explicit teaching frameworks, Illustration--Interaction--Induction (III) and Present--Practice--Produce (PPP) used to teach the same spoken discourse markers (DMs) to two different groups of…

A Framework for Explicit Vocabulary Instruction with English Language Learners

ERIC Educational Resources Information Center

Nisbet, Deanna L.; Tindall, Evie R.

2015-01-01

Academic vocabulary development is critical to the success of all learners--particularly English language learners (ELLs). This article presents a framework for integrating explicit academic vocabulary instruction for ELLs into middle school classrooms. The framework embodies five research-based principles and serves as a vehicle for structuring…

Making the Tacit Explicit: Rethinking Culturally Inclusive Pedagogy in International Student Academic Adaptation

ERIC Educational Resources Information Center

Blasco, Maribel

2015-01-01

The article proposes an approach, broadly inspired by culturally inclusive pedagogy, to facilitate international student academic adaptation based on rendering tacit aspects of local learning cultures explicit to international full degree students, rather than adapting them. Preliminary findings are presented from a focus group-based exploratory…

A self-learning rule base for command following in dynamical systems

NASA Technical Reports Server (NTRS)

Tsai, Wei K.; Lee, Hon-Mun; Parlos, Alexander

1992-01-01

In this paper, a self-learning Rule Base for command following in dynamical systems is presented. The learning is accomplished though reinforcement learning using an associative memory called SAM. The main advantage of SAM is that it is a function approximator with explicit storage of training samples. A learning algorithm patterned after the dynamic programming is proposed. Two artificially created, unstable dynamical systems are used for testing, and the Rule Base was used to generate a feedback control to improve the command following ability of the otherwise uncontrolled systems. The numerical results are very encouraging. The controlled systems exhibit a more stable behavior and a better capability to follow reference commands. The rules resulting from the reinforcement learning are explicitly stored and they can be modified or augmented by human experts. Due to overlapping storage scheme of SAM, the stored rules are similar to fuzzy rules.

Contingency blindness: location-identity binding mismatches obscure awareness of spatial contingencies and produce profound interference in visual working memory.

PubMed

Fiacconi, Chris M; Milliken, Bruce

2012-08-01

The purpose of the present study was to highlight the role of location-identity binding mismatches in obscuring explicit awareness of a strong contingency. In a spatial-priming procedure, we introduced a high likelihood of location-repeat trials. Experiments 1, 2a, and 2b demonstrated that participants' explicit awareness of this contingency was heavily influenced by the local match in location-identity bindings. In Experiment 3, we sought to determine why location-identity binding mismatches produce such low levels of contingency awareness. Our results suggest that binding mismatches can interfere substantially with visual-memory performance. We attribute the low levels of contingency awareness to participants' inability to remember the critical location-identity binding in the prime on a trial-to-trial basis. These results imply a close interplay between object files and visual working memory.

Enhancement of low visibility aerial images using histogram truncation and an explicit Retinex representation for balancing contrast and color consistency

NASA Astrophysics Data System (ADS)

Liu, Changjiang; Cheng, Irene; Zhang, Yi; Basu, Anup

2017-06-01

This paper presents an improved multi-scale Retinex (MSR) based enhancement for ariel images under low visibility. For traditional multi-scale Retinex, three scales are commonly employed, which limits its application scenarios. We extend our research to a general purpose enhanced method, and design an MSR with more than three scales. Based on the mathematical analysis and deductions, an explicit multi-scale representation is proposed that balances image contrast and color consistency. In addition, a histogram truncation technique is introduced as a post-processing strategy to remap the multi-scale Retinex output to the dynamic range of the display. Analysis of experimental results and comparisons with existing algorithms demonstrate the effectiveness and generality of the proposed method. Results on image quality assessment proves the accuracy of the proposed method with respect to both objective and subjective criteria.

Time course of implicit processing and explicit processing of emotional faces and emotional words.

PubMed

Frühholz, Sascha; Jellinghaus, Anne; Herrmann, Manfred

2011-05-01

Facial expressions are important emotional stimuli during social interactions. Symbolic emotional cues, such as affective words, also convey information regarding emotions that is relevant for social communication. Various studies have demonstrated fast decoding of emotions from words, as was shown for faces, whereas others report a rather delayed decoding of information about emotions from words. Here, we introduced an implicit (color naming) and explicit task (emotion judgment) with facial expressions and words, both containing information about emotions, to directly compare the time course of emotion processing using event-related potentials (ERP). The data show that only negative faces affected task performance, resulting in increased error rates compared to neutral faces. Presentation of emotional faces resulted in a modulation of the N170, the EPN and the LPP components and these modulations were found during both the explicit and implicit tasks. Emotional words only affected the EPN during the explicit task, but a task-independent effect on the LPP was revealed. Finally, emotional faces modulated source activity in the extrastriate cortex underlying the generation of the N170, EPN and LPP components. Emotional words led to a modulation of source activity corresponding to the EPN and LPP, but they also affected the N170 source on the right hemisphere. These data show that facial expressions affect earlier stages of emotion processing compared to emotional words, but the emotional value of words may have been detected at early stages of emotional processing in the visual cortex, as was indicated by the extrastriate source activity. Copyright © 2011 Elsevier B.V. All rights reserved.

Interaction between catechol-O-methyltransferase (COMT) Val158Met genotype and genetic vulnerability to schizophrenia during explicit processing of aversive facial stimuli.

PubMed

Lo Bianco, L; Blasi, G; Taurisano, P; Di Giorgio, A; Ferrante, F; Ursini, G; Fazio, L; Gelao, B; Romano, R; Papazacharias, A; Caforio, G; Sinibaldi, L; Popolizio, T; Bellantuono, C; Bertolino, A

2013-02-01

Emotion dysregulation is a key feature of schizophrenia, a brain disorder strongly associated with genetic risk and aberrant dopamine signalling. Dopamine is inactivated by catechol-O-methyltransferase (COMT), whose gene contains a functional polymorphism (COMT Val158Met) associated with differential activity of the enzyme and with brain physiology of emotion processing. The aim of the present study was to investigate whether genetic risk for schizophrenia and COMT Val158Met genotype interact on brain activity during implicit and explicit emotion processing. A total of 25 patients with schizophrenia, 23 healthy siblings of patients and 24 comparison subjects genotyped for COMT Val158Met underwent functional magnetic resonance imaging during implicit and explicit processing of facial stimuli with negative emotional valence. We found a main effect of diagnosis in the right amygdala, with decreased activity in patients and siblings compared with control subjects. Furthermore, a genotype × diagnosis interaction was found in the left middle frontal gyrus, such that the effect of genetic risk for schizophrenia was evident in the context of the Val/Val genotype only, i.e. the phenotype of reduced activity was present especially in Val/Val patients and siblings. Finally, a complete inversion of the COMT effect between patients and healthy subjects was found in the left striatum during explicit processing. Overall, these results suggest complex interactions between genetically determined dopamine signalling and risk for schizophrenia on brain activity in the prefrontal cortex during emotion processing. On the other hand, the effects in the striatum may represent state-related epiphenomena of the disorder itself.

Assessing the Formation of Experience-Based Gender Expectations in an Implicit Learning Scenario

PubMed Central

Öttl, Anton; Behne, Dawn M.

2017-01-01

The present study investigates the formation of new word-referent associations in an implicit learning scenario, using a gender-coded artificial language with spoken words and visual referents. Previous research has shown that when participants are explicitly instructed about the gender-coding system underlying an artificial lexicon, they monitor the frequency of exposure to male vs. female referents within this lexicon, and subsequently use this probabilistic information to predict the gender of an upcoming referent. In an explicit learning scenario, the auditory and visual gender cues are necessarily highlighted prior to acqusition, and the effects previously observed may therefore depend on participants' overt awareness of these cues. To assess whether the formation of experience-based expectations is dependent on explicit awareness of the underlying coding system, we present data from an experiment in which gender-coding was acquired implicitly, thereby reducing the likelihood that visual and auditory gender cues are used strategically during acquisition. Results show that even if the gender coding system was not perfectly mastered (as reflected in the number of gender coding errors), participants develop frequency based expectations comparable to those previously observed in an explicit learning scenario. In line with previous findings, participants are quicker at recognizing a referent whose gender is consistent with an induced expectation than one whose gender is inconsistent with an induced expectation. At the same time however, eyetracking data suggest that these expectations may surface earlier in an implicit learning scenario. These findings suggest that experience-based expectations are robust against manner of acquisition, and contribute to understanding why similar expectations observed in the activation of stereotypes during the processing of natural language stimuli are difficult or impossible to suppress. PMID:28936186

HPF Implementation of ARC3D

NASA Technical Reports Server (NTRS)

Frumkin, Michael; Yan, Jerry

1999-01-01

We present an HPF (High Performance Fortran) implementation of ARC3D code along with the profiling and performance data on SGI Origin 2000. Advantages and limitations of HPF as a parallel programming language for CFD applications are discussed. For achieving good performance results we used the data distributions optimized for implementation of implicit and explicit operators of the solver and boundary conditions. We compare the results with MPI and directive based implementations.

EdgeMaps: visualizing explicit and implicit relations

NASA Astrophysics Data System (ADS)

Dörk, Marian; Carpendale, Sheelagh; Williamson, Carey

2011-01-01

In this work, we introduce EdgeMaps as a new method for integrating the visualization of explicit and implicit data relations. Explicit relations are specific connections between entities already present in a given dataset, while implicit relations are derived from multidimensional data based on shared properties and similarity measures. Many datasets include both types of relations, which are often difficult to represent together in information visualizations. Node-link diagrams typically focus on explicit data connections, while not incorporating implicit similarities between entities. Multi-dimensional scaling considers similarities between items, however, explicit links between nodes are not displayed. In contrast, EdgeMaps visualize both implicit and explicit relations by combining and complementing spatialization and graph drawing techniques. As a case study for this approach we chose a dataset of philosophers, their interests, influences, and birthdates. By introducing the limitation of activating only one node at a time, interesting visual patterns emerge that resemble the aesthetics of fireworks and waves. We argue that the interactive exploration of these patterns may allow the viewer to grasp the structure of a graph better than complex node-link visualizations.

Reexamination of quantum bit commitment: The possible and the impossible

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

D'Ariano, Giacomo Mauro; Kretschmann, Dennis; Institut fuer Mathematische Physik, Technische Universitaet Braunschweig, Mendelssohnstrasse 3, 38106 Braunschweig

2007-09-15

Bit commitment protocols whose security is based on the laws of quantum mechanics alone are generally held to be impossible. We give a strengthened and explicit proof of this result. We extend its scope to a much larger variety of protocols, which may have an arbitrary number of rounds, in which both classical and quantum information is exchanged, and which may include aborts and resets. Moreover, we do not consider the receiver to be bound to a fixed 'honest' strategy, so that 'anonymous state protocols', which were recently suggested as a possible way to beat the known no-go results, aremore » also covered. We show that any concealing protocol allows the sender to find a cheating strategy, which is universal in the sense that it works against any strategy of the receiver. Moreover, if the concealing property holds only approximately, the cheat goes undetected with a high probability, which we explicitly estimate. The proof uses an explicit formalization of general two-party protocols, which is applicable to more general situations, and an estimate about the continuity of the Stinespring dilation of a general quantum channel. The result also provides a natural characterization of protocols that fall outside the standard setting of unlimited available technology and thus may allow secure bit commitment. We present such a protocol whose security, perhaps surprisingly, relies on decoherence in the receiver's laboratory.« less

Preliminary study of the use of the STAR-100 computer for transonic flow calculations

NASA Technical Reports Server (NTRS)

Keller, J. D.; Jameson, A.

1977-01-01

An explicit method for solving the transonic small-disturbance potential equation is presented. This algorithm, which is suitable for the new vector-processor computers such as the CDC STAR-100, is compared to successive line over-relaxation (SLOR) on a simple test problem. The convergence rate of the explicit scheme is slower than that of SLOR, however, the efficiency of the explicit scheme on the STAR-100 computer is sufficient to overcome the slower convergence rate and allow an overall speedup compared to SLOR on the CYBER 175 computer.

Toward an Optimal Pedagogy for Teamwork.

PubMed

Earnest, Mark A; Williams, Jason; Aagaard, Eva M

2017-10-01

Teamwork and collaboration are increasingly listed as core competencies for undergraduate health professions education. Despite the clear mandate for teamwork training, the optimal method for providing that training is much less certain. In this Perspective, the authors propose a three-level classification of pedagogical approaches to teamwork training based on the presence of two key learning factors: interdependent work and explicit training in teamwork. In this classification framework, level 1-minimal team learning-is where learners work in small groups but neither of the key learning factors is present. Level 2-implicit team learning-engages learners in interdependent learning activities but does not include an explicit focus on teamwork. Level 3-explicit team learning-creates environments where teams work interdependently toward common goals and are given explicit instruction and practice in teamwork. The authors provide examples that demonstrate each level. They then propose that the third level of team learning, explicit team learning, represents a best practice approach in teaching teamwork, highlighting their experience with an explicit team learning course at the University of Colorado Anschutz Medical Campus. Finally, they discuss several challenges to implementing explicit team-learning-based curricula: the lack of a common teamwork model on which to anchor such a curriculum; the question of whether the knowledge, skills, and attitudes acquired during training would be transferable to the authentic clinical environment; and effectively evaluating the impact of explicit team learning.

Do Implicit Attitudes Predict Actual Voting Behavior Particularly for Undecided Voters?

PubMed Central

Friese, Malte; Smith, Colin Tucker; Plischke, Thomas; Bluemke, Matthias; Nosek, Brian A.

2012-01-01

The prediction of voting behavior of undecided voters poses a challenge to psychologists and pollsters. Recently, researchers argued that implicit attitudes would predict voting behavior particularly for undecided voters whereas explicit attitudes would predict voting behavior particularly for decided voters. We tested this assumption in two studies in two countries with distinct political systems in the context of real political elections. Results revealed that (a) explicit attitudes predicted voting behavior better than implicit attitudes for both decided and undecided voters, and (b) implicit attitudes predicted voting behavior better for decided than undecided voters. We propose that greater elaboration of attitudes produces stronger convergence between implicit and explicit attitudes resulting in better predictive validity of both, and less incremental validity of implicit over explicit attitudes for the prediction of voting behavior. However, greater incremental predictive validity of implicit over explicit attitudes may be associated with less elaboration. PMID:22952898

How big and how close? Habitat patch size and spacing to conserve a threatened species

Treesearch

Bruce G. Marcot; Martin G. Raphael; Nathan H. Schumaker; Beth Galleher

2013-01-01

We present results of a spatially explicit, individual-based stochastic dispersal model (HexSim) to evaluate effects of size and spacing of patches of habitat of Northern Spotted Owls (NSO; Strix occidentalis caurina) in Pacific Northwest, USA, to help advise recovery planning efforts. We modeled 31 artificial landscape scenarios representing...

Stability of large-scale systems.

NASA Technical Reports Server (NTRS)

Siljak, D. D.

1972-01-01

The purpose of this paper is to present the results obtained in stability study of large-scale systems based upon the comparison principle and vector Liapunov functions. The exposition is essentially self-contained, with emphasis on recent innovations which utilize explicit information about the system structure. This provides a natural foundation for the stability theory of dynamic systems under structural perturbations.

The Effects of Expectancy-Incongruent Feedback and Self-Affirmation on Task Performance of Secondary School Students

ERIC Educational Resources Information Center

Baadte, Christiane; Kurenbach, Friederike

2017-01-01

In the present study, the assumption was tested that expectancy-incongruent feedback in conjunction with explicit self-affirmation directs attention away from the task and to the self. As a result, performance should decrease in resource-sensitive text/picture comprehension tasks as compared to resource-insensitive tasks. Three hundred and…

Effectiveness of a Conceptual Change-Oriented Teaching Strategy to Improve Students' Understanding of Galvanic Cells

ERIC Educational Resources Information Center

Ozkaya, Ali Riza; Uce, Musa; Saricayir, Hakan; Sahin, Musa

2006-01-01

The results of previous educational research raise some questions about the efficacy of conventional teaching strategies and point to a need for using teaching strategies that explicitly take into account misconceptions students bring to the classes or acquire during the teaching-learning process. Accordingly, this article presents efforts to…

Explicit formulae for Yang-Mills-Einstein amplitudes from the double copy

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

Chiodaroli, Marco; Günaydin, Murat; Johansson, Henrik

Using the double-copy construction of Yang-Mills-Einstein theories formulated in our earlier work, we obtain compact presentations for single-trace Yang-Mills-Einstein tree amplitudes with up to five external gravitons and an arbitrary number of gluons. These are written as linear combinations of color-ordered Yang-Mills trees, where the coefficients are given by color/kinematics-satisfying numerators in a Yang-Mills + φ 3 theory. The construction outlined in this paper holds in general dimension and extends straightforwardly to supergravity theories. For one, two, and three external gravitons, our expressions give identical or simpler presentations of amplitudes already constructed through string-theory considerations or the scattering equations formalism.more » Our results are based on color/kinematics duality and gauge invariance, and strongly hint at a recursive structure underlying the single-trace amplitudes with an arbitrary number of gravitons. We also present explicit expressions for all-loop single-graviton Einstein-Yang-Mills amplitudes in terms of Yang-Mills amplitudes and, through gauge invariance, derive new all-loop amplitude relations for Yang-Mills theory.« less

Explicit formulae for Yang-Mills-Einstein amplitudes from the double copy

DOE PAGES

Chiodaroli, Marco; Günaydin, Murat; Johansson, Henrik; ...

2017-07-03

Using the double-copy construction of Yang-Mills-Einstein theories formulated in our earlier work, we obtain compact presentations for single-trace Yang-Mills-Einstein tree amplitudes with up to five external gravitons and an arbitrary number of gluons. These are written as linear combinations of color-ordered Yang-Mills trees, where the coefficients are given by color/kinematics-satisfying numerators in a Yang-Mills + φ 3 theory. The construction outlined in this paper holds in general dimension and extends straightforwardly to supergravity theories. For one, two, and three external gravitons, our expressions give identical or simpler presentations of amplitudes already constructed through string-theory considerations or the scattering equations formalism.more » Our results are based on color/kinematics duality and gauge invariance, and strongly hint at a recursive structure underlying the single-trace amplitudes with an arbitrary number of gravitons. We also present explicit expressions for all-loop single-graviton Einstein-Yang-Mills amplitudes in terms of Yang-Mills amplitudes and, through gauge invariance, derive new all-loop amplitude relations for Yang-Mills theory.« less

Implicit versus explicit frequency comparisons: two mechanisms of auditory change detection.

PubMed

Demany, Laurent; Semal, Catherine; Pressnitzer, Daniel

2011-04-01

Listeners had to compare, with respect to pitch (frequency), a pure tone (T) to a combination of pure tones presented subsequently (C). The elements of C were either synchronous, and therefore difficult to hear out individually, or asynchronous and therefore easier to hear out individually. In the "present/absent" condition, listeners had to judge if T reappeared in C or not. In the "up/down" condition, the task was to judge if the element of C most similar to T was higher or lower than T. When the elements of C were synchronous, the up/down task was found to be easier than the present/absent task; the converse result was obtained when the elements of C were asynchronous. This provides evidence for a duality of auditory comparisons between tone frequencies: (1) implicit comparisons made by automatic and direction-sensitive "frequency-shift detectors"; (2) explicit comparisons more sensitive to the magnitude of a frequency change than to its direction. Another experiment suggests that although the frequency-shift detectors cannot compare effectively two tones separated by an interfering tone, they are largely insensitive to interfering noise bursts.

Three-stage stochastic pump: Another type of Onsager-Casimir symmetry and results far from equilibrium

NASA Astrophysics Data System (ADS)

Rosas, Alexandre; Van den Broeck, Christian; Lindenberg, Katja

2018-06-01

The stochastic thermodynamic analysis of a time-periodic single particle pump sequentially exposed to three thermochemical reservoirs is presented. The analysis provides explicit results for flux, thermodynamic force, entropy production, work, and heat. These results apply near equilibrium as well as far from equilibrium. In the linear response regime, a different type of Onsager-Casimir symmetry is uncovered. The Onsager matrix becomes symmetric in the limit of zero dissipation.

Coincident Extraction of Line Objects from Stereo Image Pairs.

DTIC Science & Technology

1983-09-01

4.4.3 Reconstruction of intersections 4.5 Final result processing 5. Presentation of the results 5.1 FIM image processing system 5.2 Extraction results in...image. To achieve this goal, the existing software system had to be modified and extended considerably. The following sections of this report will give...8000 pixels of each image without explicit loading of subimages could not yet be performed due to computer system software problems. m m n m -4- The

Defensive function of persecutory delusion and discrepancy between explicit and implicit self-esteem in schizophrenia: study using the Brief Implicit Association Test

PubMed Central

Nakamura, Mitsuo; Hayakawa, Tomomi; Okamura, Aiko; Kohigashi, Mutsumi; Fukui, Kenji; Narumoto, Jin

2015-01-01

Background If delusions serve as a defense mechanism in schizophrenia patients with paranoia, then they should show normal or high explicit self-esteem and low implicit self-esteem. However, the results of previous studies are inconsistent. One possible explanation for this inconsistency is that there are two types of paranoia, “bad me” (self-blaming) paranoia and “poor me” (non-self-blaming) paranoia. We thus examined implicit and explicit self-esteem and self-blaming tendency in patients with schizophrenia and schizoaffective disorder. We hypothesized that patients with paranoia would show lower implicit self-esteem and only those with non-self-blaming paranoia would experience a discrepancy between explicit and implicit self-esteem. Methods Participants consisted of patients with schizophrenia and schizoaffective disorder recruited from a day hospital (N=71). Participants were assessed for psychotic symptoms, using the Brief Psychiatric Rating Scale (BPRS), and self-blaming tendency, using the brief COPE. We also assessed explicit self-esteem, using the Rosenberg Self-Esteem Scale (RSES), implicit self-esteem, using Brief Implicit Association Test (BIAT), and discrepancy between explicit and implicit self-esteem. Results Contrary to our hypothesis, implicit self-esteem in paranoia and nonparanoia showed no statistical difference. As expected, only patients with non-self-blaming paranoia experienced a discrepancy between explicit and implicit self-esteem; other groups showed no such discrepancy. Conclusion These results suggest that persecutory delusion plays a defensive role in non-self-blaming paranoia. PMID:25565849

From ideal to real: a longitudinal study of the role of implicit leadership theories on leader-member exchanges and employee outcomes.

PubMed

Epitropaki, Olga; Martin, Robin

2005-07-01

The results of the present longitudinal study demonstrate the importance of implicit leadership theories (ILTs) for the quality of leader-member exchanges (LMX) and employees' organizational commitment, job satisfaction, and well-being. Results based on a sample of 439 employees who completed the study questionnaires at 2 time points showed that the closer employees perceived their actual manager's profile to be to the ILTs they endorsed, the better the quality of LMX. Results also indicated that the implicit-explicit leadership traits difference had indirect effects on employee attitudes and well-being. These findings were consistent across employee groups that differed in terms of job demand and the duration of manager-employee relation, but not in terms of motivation. Furthermore, crossed-lagged modeling analyses of the longitudinal data explored the possibility of reciprocal effects between implicit-explicit leadership traits difference and LMX and provided support for the initially hypothesized direction of causal effects. Copyright 2005 APA, all rights reserved.

[Verification of the double dissociation model of shyness using the implicit association test].

PubMed

Fujii, Tsutomu; Aikawa, Atsushi

2013-12-01

The "double dissociation model" of shyness proposed by Asendorpf, Banse, and Mtücke (2002) was demonstrated in Japan by Aikawa and Fujii (2011). However, the generalizability of the double dissociation model of shyness was uncertain. The present study examined whether the results reported in Aikawa and Fujii (2011) would be replicated. In Study 1, college students (n = 91) completed explicit self-ratings of shyness and other personality scales. In Study 2, forty-eight participants completed IAT (Implicit Association Test) for shyness, and their friends (n = 141) rated those participants on various personality scales. The results revealed that only the explicit self-concept ratings predicted other-rated low praise-seeking behavior, sociable behavior and high rejection-avoidance behavior (controlled shy behavior). Only the implicit self-concept measured by the shyness IAT predicted other-rated high interpersonal tension (spontaneous shy behavior). The results of this study are similar to the findings of the previous research, which supports generalizability of the double dissociation model of shyness.

Dynamic analysis of lunar lander during soft landing using explicit finite element method

NASA Astrophysics Data System (ADS)

Zheng, Guang; Nie, Hong; Chen, Jinbao; Chen, Chuanzhi; Lee, Heow Pueh

2018-07-01

In this paper, the soft-landing analysis of a lunar lander spacecraft under three loading case was carried out in ABAQUS, using the Explicit Finite Element method. To ensure the simulation result's accuracy and reliability, the energy and mass balance criteria of the model was presented along with the theory and calculation method, and the results were benchmarked with other software (LS-DYNA) to get a validated model. The results from three loading case showed that the energy and mass of the models were conserved during soft landing, which satisfies the energy and mass balance criteria. The overloading response, structure steady state, and the crushing stroke of this lunar lander all met the design requirements of the lunar lander. The buffer energy-absorbing properties in this model have a good energy-absorbing capability, in which up to 84% of the initial energy could be dissipated. The design parameters of the model could guide the design of future manned landers or larger lunar landers.

On common noise-induced synchronization in complex networks with state-dependent noise diffusion processes

NASA Astrophysics Data System (ADS)

Russo, Giovanni; Shorten, Robert

2018-04-01

This paper is concerned with the study of common noise-induced synchronization phenomena in complex networks of diffusively coupled nonlinear systems. We consider the case where common noise propagation depends on the network state and, as a result, the noise diffusion process at the nodes depends on the state of the network. For such networks, we present an algebraic sufficient condition for the onset of synchronization, which depends on the network topology, the dynamics at the nodes, the coupling strength and the noise diffusion. Our result explicitly shows that certain noise diffusion processes can drive an unsynchronized network towards synchronization. In order to illustrate the effectiveness of our result, we consider two applications: collective decision processes and synchronization of chaotic systems. We explicitly show that, in the former application, a sufficiently large noise can drive a population towards a common decision, while, in the latter, we show how common noise can synchronize a network of Lorentz chaotic systems.

The mere exposure effect is sensitive to color information: evidence for color effects in a perceptual implicit memory test.

PubMed

Hupbach, Almut; Melzer, André; Hardt, Oliver

2006-01-01

Priming effects in perceptual tests of implicit memory are assumed to be perceptually specific. Surprisingly, changing object colors from study to test did not diminish priming in most previous studies. However, these studies used implicit tests that are based on object identification, which mainly depends on the analysis of the object shape and therefore operates color-independently. The present study shows that color effects can be found in perceptual implicit tests when the test task requires the processing of color information. In Experiment 1, reliable color priming was found in a mere exposure design (preference test). In Experiment 2, the preference test was contrasted with a conceptually driven color-choice test. Altering the shape of object from study to test resulted in significant priming in the color-choice test but eliminated priming in the preference test. Preference judgments thus largely depend on perceptual processes. In Experiment 3, the preference and the color-choice test were studied under explicit test instructions. Differences in reaction times between the implicit and the explicit test suggest that the implicit test results were not an artifact of explicit retrieval attempts. In contrast with previous assumptions, it is therefore concluded that color is part of the representation that mediates perceptual priming.

Explicitly-correlated Gaussian geminals in electronic structure calculations

NASA Astrophysics Data System (ADS)

Szalewicz, Krzysztof; Jeziorski, Bogumił

2010-11-01

Explicitly correlated functions have been used since 1929, but initially only for two-electron systems. In 1960, Boys and Singer showed that if the correlating factor is of Gaussian form, many-electron integrals can be computed for general molecules. The capability of explicitly correlated Gaussian (ECG) functions to accurately describe many-electron atoms and molecules was demonstrated only in the early 1980s when Monkhorst, Zabolitzky and the present authors cast the many-body perturbation theory (MBPT) and coupled cluster (CC) equations as a system of integro-differential equations and developed techniques of solving these equations with two-electron ECG functions (Gaussian-type geminals, GTG). This work brought a new accuracy standard to MBPT/CC calculations. In 1985, Kutzelnigg suggested that the linear r 12 correlating factor can also be employed if n-electron integrals, n > 2, are factorised with the resolution of identity. Later, this factor was replaced by more general functions f (r 12), most often by ? , usually represented as linear combinations of Gaussian functions which makes the resulting approach (called F12) a special case of the original GTG expansion. The current state-of-art is that, for few-electron molecules, ECGs provide more accurate results than any other basis available, but for larger systems the F12 approach is the method of choice, giving significant improvements over orbital calculations.

Explicit and implicit learning: The case of computer programming

NASA Astrophysics Data System (ADS)

Mancy, Rebecca

The central question of this thesis concerns the role of explicit and implicit learning in the acquisition of a complex skill, namely computer programming. This issue is explored with reference to information processing models of memory drawn from cognitive science. These models indicate that conscious information processing occurs in working memory where information is stored and manipulated online, but that this mode of processing shows serious limitations in terms of capacity or resources. Some information processing models also indicate information processing in the absence of conscious awareness through automation and implicit learning. It was hypothesised that students would demonstrate implicit and explicit knowledge and that both would contribute to their performance in programming. This hypothesis was investigated via two empirical studies. The first concentrated on temporary storage and online processing in working memory and the second on implicit and explicit knowledge. Storage and processing were tested using two tools: temporary storage capacity was measured using a digit span test; processing was investigated with a disembedding test. The results were used to calculate correlation coefficients with performance on programming examinations. Individual differences in temporary storage had only a small role in predicting programming performance and this factor was not a major determinant of success. Individual differences in disembedding were more strongly related to programming achievement. The second study used interviews to investigate the use of implicit and explicit knowledge. Data were analysed according to a grounded theory paradigm. The results indicated that students possessed implicit and explicit knowledge, but that the balance between the two varied between students and that the most successful students did not necessarily possess greater explicit knowledge. The ways in which students described their knowledge led to the development of a framework which extends beyond the implicit-explicit dichotomy to four descriptive categories of knowledge along this dimension. Overall, the results demonstrated that explicit and implicit knowledge both contribute to the acquisition ofprogramming skills. Suggestions are made for further research, and the results are discussed in the context of their implications for education.

A Metacognitive Approach to "Implicit" and "Explicit" Evaluations: Comment on Gawronski and Bodenhausen (2006)

ERIC Educational Resources Information Center

Petty, Richard E.; Brinol, Pablo

2006-01-01

Comments on the article by B. Gawronski and G. V. Bodenhausen (see record 2006-10465-003). A metacognitive model (MCM) is presented to describe how automatic (implicit) and deliberative (explicit) measures of attitudes respond to change attempts. The model assumes that contemporary implicit measures tap quick evaluative associations, whereas…

The Effects of Vocabulary Instructions on Students' Reading Comprehension across Cognitive Styles in ESP

ERIC Educational Resources Information Center

Kusumawati, Eny; Widiati, Utami

2017-01-01

Many scholars in language learning and teaching agree that vocabulary plays a vital role in a language learning. However, the way the vocabulary is presented to language learners, whether explicitly or implicitly, becomes central discussion in language literature. This study investigated the effect of explicit and implicit vocabulary instructions…

Explicitly Teaching Social Skills Schoolwide: Using a Matrix to Guide Instruction

ERIC Educational Resources Information Center

Simonsen, Brandi; Myers, Diane; Everett, Susannah; Sugai, George; Spencer, Rebecca; LaBreck, Chris

2012-01-01

Socially skilled students are more successful in school. Just like academic skills, social skills need to be explicitly taught. Students, including students who display at-risk behavior, benefit when social skills instruction is delivered schoolwide as part of a comprehensive intervention approach. This article presents a seven-step action…

An explicit microphysics thunderstorm model.

Treesearch

R. Solomon; C.M. Medaglia; C. Adamo; S. Dietrick; A. Mugnai; U. Biader Ceipidor

2005-01-01

The authors present a brief description of a 1.5-dimensional thunderstorm model with a lightning parameterization that utilizes an explicit microphysical scheme to model lightning-producing clouds. The main intent of this work is to describe the basic microphysical and electrical properties of the model, with a small illustrative section to show how the model may be...

Elementary teachers' perceptions about the effective features of explicit-reflective nature of science instruction

NASA Astrophysics Data System (ADS)

Adibelli-Sahin, Elif; Deniz, Hasan

2017-04-01

This qualitative study explored elementary teachers' perceptions about the effective features of explicit-reflective nature of science (NOS) instruction. Our participants were four elementary teachers from a public charter school located in the Southwestern U.S.A. The four elementary teachers participated in an academic year-long professional development about NOS which consisted of NOS training and NOS teaching phases. After each phase of the professional development, we specifically asked our participants which features of the explicit-reflective NOS instruction they found effective in improving their NOS conceptions by presenting pre- and post-profiles of their NOS conceptions. We identified nine features perceived by the participants as effective components of explicit-reflective NOS instruction: (1) specific focus on NOS content, (2) participation in hands-on NOS activities, (3) introductory NOS readings, (4) multiple types/forms of reflection, (5) multiple exposure to NOS content, (6) structural consistency in the presentation of NOS content, (7) the evaluation of secondary NOS data from elementary students, (8) the analysis of national and state science standards in terms of NOS content, and (9) NOS teaching experience.

Controlled and implicit processes in evaluative conditioning on implicit and explicit attitudes toward alcohol and intentions to drink.

PubMed

Zerhouni, Oulmann; Bègue, Laurent; Comiran, Francisco; Wiers, Reinout W

2018-01-01

Since implicit attitudes (i.e. evaluations occurring outside of complete awareness) are highly predictive of alcohol consumption, we tested an evaluative learning procedure based on repeated pairing to a critical stimulus (i.e. alcohol, the CS) with a valenced stimulus (the US) in order to modify implicit attitudes (i.e. evaluative conditioning; EC). We hypothesized that manipulating the learning context to bolster implicit affect misattribution should strengthen EC effects on implicit attitudes toward alcohol, while encouraging deliberate processing of CS-US pairs, should strengthen EC effects on explicit attitudes. In our study (n=114 students) we manipulated whether CS-US pairs were presented simultaneously or sequentially. Recollective memory was estimated with a Process Dissociation Procedure. Both implicit and explicit attitudes were assessed immediately after the procedure. Behavioral intentions were measured directly after and one week after the EC-procedure. We found that EC with sequential presentation had a stronger impact on implicit and explicit measures and on purchase intentions immediately after the procedure and one week after. The present findings provide new evidence that (i) EC is an effective way to change implicit attitudes toward alcohol and (ii) evidence that EC may be better described by propositional rather than dual process accounts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preserved memory-based orienting of attention with impaired explicit memory in healthy ageing.

PubMed

Salvato, Gerardo; Patai, Eva Z; Nobre, Anna C

2016-01-01

It is increasingly recognised that spatial contextual long-term memory (LTM) prepares neural activity for guiding visuo-spatial attention in a proactive manner. In the current study, we investigated whether the decline in explicit memory observed in healthy ageing would compromise this mechanism. We compared the behavioural performance of younger and older participants on learning new contextual memories, on orienting visual attention based on these learnt contextual associations, and on explicit recall of contextual memories. We found a striking dissociation between older versus younger participants in the relationship between the ability to retrieve contextual memories versus the ability to use these to guide attention to enhance performance on a target-detection task. Older participants showed significant deficits in the explicit retrieval task, but their behavioural benefits from memory-based orienting of attention were equivalent to those in young participants. Furthermore, memory-based orienting correlated significantly with explicit contextual LTM in younger adults but not in older adults. These results suggest that explicit memory deficits in ageing might not compromise initial perception and encoding of events. Importantly, the results also shed light on the mechanisms of memory-guided attention, suggesting that explicit contextual memories are not necessary. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Hyperbolic heat conduction problems involving non-Fourier effects - Numerical simulations via explicit Lax-Wendroff/Taylor-Galerkin finite element formulations

NASA Technical Reports Server (NTRS)

Tamma, Kumar K.; Namburu, Raju R.

1989-01-01

Numerical simulations are presented for hyperbolic heat-conduction problems that involve non-Fourier effects, using explicit, Lax-Wendroff/Taylor-Galerkin FEM formulations as the principal computational tool. Also employed are smoothing techniques which stabilize the numerical noise and accurately predict the propagating thermal disturbances. The accurate capture of propagating thermal disturbances at characteristic time-step values is achieved; numerical test cases are presented which validate the proposed hyperbolic heat-conduction problem concepts.

Pictures cueing threat: brain dynamics in viewing explicitly instructed danger cues

PubMed Central

Schupp, Harald T.

2012-01-01

Recent event-related brain potential studies revealed the selective processing of emotional and threatening pictures. Integrating the picture viewing and threat-of-shock paradigm, the present study examined the processing of emotional pictures while they were explicitly instructed to cue threat of real world danger (i.e. electric shocks). Toward this end, 60 pleasant, neutral and unpleasant IAPS-pictures were presented (1 s) as a continuous random stream while high-density EEG and self-reported threat were assessed. In three experimental runs, each picture category was used once as a threat-cue, whereas in the other conditions the same category served as safety-cue. An additional passive viewing run served as a no-threat condition, thus, establishing a threat–safety continuum (threat-cue–safety-cue–no-threat) for each picture category. Threat-of-shock modulated P1, P2 and parieto-occipital LPP amplitudes. While the P1 component differentiated among threat- and no-threat conditions, the P2 and LPP effects were specific to pictures signaling threat-of-shock. Thus, stimulus processing progressively gained more accurate information about environmental threat conditions. Interestingly, the finding of increased EPN and centro-parietal LPP amplitudes to emotional pictures was independent from threat-of-shock manipulation. Accordingly, the results indicate distinct effects associated with the intrinsic significance of emotional pictures and explicitly instructed threat contingencies. PMID:21719425

Explicit and implicit assessment of gender roles.

PubMed

Fernández, Juan; Quiroga, M Ángeles; Escorial, Sergio; Privado, Jesús

2014-05-01

Gender roles have been assessed by explicit measures and, recently, by implicit measures. In the former case, the theoretical assumptions have been questioned by empirical results. To solve this contradiction, we carried out two concatenated studies based on a relatively well-founded theoretical and empirical approach. The first study was designed to obtain a sample of genderized activities of the domestic sphere by means of an explicit assessment. Forty-two raters (22 women and 20 men, balanced on age, sex, and level of education) took part as raters. In the second study, an implicit assessment of gender roles was carried out, focusing on the response time given to the sample activities obtained from the first study. A total of 164 adults (90 women and 74 men, mean age = 43), with experience in living with a partner and balanced on age, sex, and level of education, participated. Taken together, results show that explicit and implicit assessment converge. The current social reality shows that there is still no equity in some gender roles in the domestic sphere. These consistent results show considerable theoretical and empirical robustness, due to the double implicit and explicit assessment.

Decisions among the Undecided: Implicit Attitudes Predict Future Voting Behavior of Undecided Voters

PubMed Central

Lundberg, Kristjen B.; Payne, B. Keith

2014-01-01

Implicit attitudes have been suggested as a key to unlock the hidden preferences of undecided voters. Past research, however, offered mixed support for this hypothesis. The present research used a large nationally representative sample and a longitudinal design to examine the predictive utility of implicit and explicit attitude measures in the 2008 U.S. presidential election. In our analyses, explicit attitudes toward candidates predicted voting better for decided than undecided voters, but implicit candidate attitudes were predictive of voting for both decided and undecided voters. Extending our examination to implicit and explicit racial attitudes, we found the same pattern. Taken together, these results provide convergent evidence that implicit attitudes predict voting about as well for undecided as for decided voters. We also assessed a novel explanation for these effects by evaluating whether implicit attitudes may predict the choices of undecided voters, in part, because they are neglected when people introspect about their confidence. Consistent with this idea, we found that the extremity of explicit but not implicit attitudes was associated with greater confidence. These analyses shed new light on the utility of implicit measures in predicting future behavior among individuals who feel undecided. Considering the prior studies together with this new evidence, the data seem to be consistent that implicit attitudes may be successful in predicting the behavior of undecided voters. PMID:24489666

Explicit and implicit reinforcement learning across the psychosis spectrum.

PubMed

Barch, Deanna M; Carter, Cameron S; Gold, James M; Johnson, Sheri L; Kring, Ann M; MacDonald, Angus W; Pizzagalli, Diego A; Ragland, J Daniel; Silverstein, Steven M; Strauss, Milton E

2017-07-01

Motivational and hedonic impairments are core features of a variety of types of psychopathology. An important aspect of motivational function is reinforcement learning (RL), including implicit (i.e., outside of conscious awareness) and explicit (i.e., including explicit representations about potential reward associations) learning, as well as both positive reinforcement (learning about actions that lead to reward) and punishment (learning to avoid actions that lead to loss). Here we present data from paradigms designed to assess both positive and negative components of both implicit and explicit RL, examine performance on each of these tasks among individuals with schizophrenia, schizoaffective disorder, and bipolar disorder with psychosis, and examine their relative relationships to specific symptom domains transdiagnostically. None of the diagnostic groups differed significantly from controls on the implicit RL tasks in either bias toward a rewarded response or bias away from a punished response. However, on the explicit RL task, both the individuals with schizophrenia and schizoaffective disorder performed significantly worse than controls, but the individuals with bipolar did not. Worse performance on the explicit RL task, but not the implicit RL task, was related to worse motivation and pleasure symptoms across all diagnostic categories. Performance on explicit RL, but not implicit RL, was related to working memory, which accounted for some of the diagnostic group differences. However, working memory did not account for the relationship of explicit RL to motivation and pleasure symptoms. These findings suggest transdiagnostic relationships across the spectrum of psychotic disorders between motivation and pleasure impairments and explicit RL. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

High Performance Programming Using Explicit Shared Memory Model on Cray T3D1

NASA Technical Reports Server (NTRS)

Simon, Horst D.; Saini, Subhash; Grassi, Charles

1994-01-01

The Cray T3D system is the first-phase system in Cray Research, Inc.'s (CRI) three-phase massively parallel processing (MPP) program. This system features a heterogeneous architecture that closely couples DEC's Alpha microprocessors and CRI's parallel-vector technology, i.e., the Cray Y-MP and Cray C90. An overview of the Cray T3D hardware and available programming models is presented. Under Cray Research adaptive Fortran (CRAFT) model four programming methods (data parallel, work sharing, message-passing using PVM, and explicit shared memory model) are available to the users. However, at this time data parallel and work sharing programming models are not available to the user community. The differences between standard PVM and CRI's PVM are highlighted with performance measurements such as latencies and communication bandwidths. We have found that the performance of neither standard PVM nor CRI s PVM exploits the hardware capabilities of the T3D. The reasons for the bad performance of PVM as a native message-passing library are presented. This is illustrated by the performance of NAS Parallel Benchmarks (NPB) programmed in explicit shared memory model on Cray T3D. In general, the performance of standard PVM is about 4 to 5 times less than obtained by using explicit shared memory model. This degradation in performance is also seen on CM-5 where the performance of applications using native message-passing library CMMD on CM-5 is also about 4 to 5 times less than using data parallel methods. The issues involved (such as barriers, synchronization, invalidating data cache, aligning data cache etc.) while programming in explicit shared memory model are discussed. Comparative performance of NPB using explicit shared memory programming model on the Cray T3D and other highly parallel systems such as the TMC CM-5, Intel Paragon, Cray C90, IBM-SP1, etc. is presented.

Effects of delays on 6-year-old children’s self-generation and retention of knowledge through integration

PubMed Central

Varga, Nicole L.; Bauer, Patricia J.

2013-01-01

The present research was an investigation of the effect of delay on self-generation and retention of knowledge derived through integration by 6-year-old children. Children were presented with novel facts from passages read aloud to them (stem facts) and tested for self-generation of new knowledge through integration of the facts. In Experiment 1, children integrated the stem facts at Session 1 and retained the self-generated memory traces over 1 week. In Experiment 2, 1-week delays were imposed either between the to-be-integrated facts (between-stem delay) or after the stem facts but before the test (before-test delay). Integration performance was diminished in both conditions. Moreover, memory for individual stem facts was lower in Experiment 2 than in Experiment 1, suggesting that self-generation through integration promoted memory for explicitly taught information. The results indicate the importance of tests for promoting self-generation through integration as well as for retaining newly self-generated and explicitly taught information. PMID:23563162

Identification of internal properties of fibers and micro-swimmers

NASA Astrophysics Data System (ADS)

Plouraboue, Franck; Thiam, Ibrahima; Delmotte, Blaise; Climent, Eric; PSC Collaboration

2016-11-01

In this presentation we discuss the identifiability of constitutive parameters of passive or active micro-swimmers. We first present a general framework for describing fibers or micro-swimmers using a bead-model description. Using a kinematic constraint formulation to describe fibers, flagellum or cilia, we find explicit linear relationship between elastic constitutive parameters and generalised velocities from computing contact forces. This linear formulation then permits to address explicitly identifiability conditions and solve for parameter identification. We show that both active forcing and passive parameters are both identifiable independently but not simultaneously. We also provide unbiased estimators for elastic parameters as well as active ones in the presence of Langevin-like forcing with Gaussian noise using normal linear regression models and maximum likelihood method. These theoretical results are illustrated in various configurations of relaxed or actuated passives fibers, and active filament of known passive properties, showing the efficiency of the proposed approach for direct parameter identification. The convergence of the proposed estimators is successfully tested numerically.

An explicit solution to the exoatmospheric powered flight guidance and trajectory optimization problem for rocket propelled vehicles

NASA Technical Reports Server (NTRS)

Jaggers, R. F.

1977-01-01

A derivation of an explicit solution to the two point boundary-value problem of exoatmospheric guidance and trajectory optimization is presented. Fixed initial conditions and continuous burn, multistage thrusting are assumed. Any number of end conditions from one to six (throttling is required in the case of six) can be satisfied in an explicit and practically optimal manner. The explicit equations converge for off nominal conditions such as engine failure, abort, target switch, etc. The self starting, predictor/corrector solution involves no Newton-Rhapson iterations, numerical integration, or first guess values, and converges rapidly if physically possible. A form of this algorithm has been chosen for onboard guidance, as well as real time and preflight ground targeting and trajectory shaping for the NASA Space Shuttle Program.

Explicit attention interferes with selective emotion processing in human extrastriate cortex

PubMed Central

Schupp, Harald T; Stockburger, Jessica; Bublatzky, Florian; Junghöfer, Markus; Weike, Almut I; Hamm, Alfons O

2007-01-01

Background Brain imaging and event-related potential studies provide strong evidence that emotional stimuli guide selective attention in visual processing. A reflection of the emotional attention capture is the increased Early Posterior Negativity (EPN) for pleasant and unpleasant compared to neutral images (~150–300 ms poststimulus). The present study explored whether this early emotion discrimination reflects an automatic phenomenon or is subject to interference by competing processing demands. Thus, emotional processing was assessed while participants performed a concurrent feature-based attention task varying in processing demands. Results Participants successfully performed the primary visual attention task as revealed by behavioral performance and selected event-related potential components (Selection Negativity and P3b). Replicating previous results, emotional modulation of the EPN was observed in a task condition with low processing demands. In contrast, pleasant and unpleasant pictures failed to elicit increased EPN amplitudes compared to neutral images in more difficult explicit attention task conditions. Further analyses determined that even the processing of pleasant and unpleasant pictures high in emotional arousal is subject to interference in experimental conditions with high task demand. Taken together, performing demanding feature-based counting tasks interfered with differential emotion processing indexed by the EPN. Conclusion The present findings demonstrate that taxing processing resources by a competing primary visual attention task markedly attenuated the early discrimination of emotional from neutral picture contents. Thus, these results provide further empirical support for an interference account of the emotion-attention interaction under conditions of competition. Previous studies revealed the interference of selective emotion processing when attentional resources were directed to locations of explicitly task-relevant stimuli. The present data suggest that interference of emotion processing by competing task demands is a more general phenomenon extending to the domain of feature-based attention. Furthermore, the results are inconsistent with the notion of effortlessness, i.e., early emotion discrimination despite concurrent task demands. These findings implicate to assess the presumed automatic nature of emotion processing at the level of specific aspects rather than considering automaticity as an all-or-none phenomenon. PMID:17316444

Implicit and explicit social mentalizing: dual processes driven by a shared neural network

PubMed Central

Van Overwalle, Frank; Vandekerckhove, Marie

2013-01-01

Recent social neuroscientific evidence indicates that implicit and explicit inferences on the mind of another person (i.e., intentions, attributions or traits), are subserved by a shared mentalizing network. Under both implicit and explicit instructions, ERP studies reveal that early inferences occur at about the same time, and fMRI studies demonstrate an overlap in core mentalizing areas, including the temporo-parietal junction (TPJ) and the medial prefrontal cortex (mPFC). These results suggest a rapid shared implicit intuition followed by a slower explicit verification processes (as revealed by additional brain activation during explicit vs. implicit inferences). These data provide support for a default-adjustment dual-process framework of social mentalizing. PMID:24062663

Why be moral? Children's explicit motives for prosocial-moral action

PubMed Central

Sengsavang, Sonia; Willemsen, Kayleen; Krettenauer, Tobias

2015-01-01

Recent research on young children's morality has stressed the autonomous and internal nature of children's moral motivation. However, this research has mostly focused on implicit moral motives, whereas children's explicit motives have not been investigated directly. This study examined children's explicit motives for why they want to engage in prosocial actions and avoid antisocial behavior. A total of 195 children aged 4–12 years were interviewed about their motives for everyday prosocial-moral actions, as well as reported on their relationship with their parents. Children's explicit motives to abstain from antisocial behavior were found to be more external and less other-oriented than their motives for prosocial action. Motives that reflected higher levels of internal motivation became more frequent with age. Moreover, positive parent-child relationships predicted more other-oriented motives and greater explication of moral motives. Overall, the study provides evidence that children's explicit moral motivation is far more heterogeneous than prominent theories of moral development (past and present) suggest. PMID:25999880

Why be moral? Children's explicit motives for prosocial-moral action.

PubMed

Sengsavang, Sonia; Willemsen, Kayleen; Krettenauer, Tobias

2015-01-01

Recent research on young children's morality has stressed the autonomous and internal nature of children's moral motivation. However, this research has mostly focused on implicit moral motives, whereas children's explicit motives have not been investigated directly. This study examined children's explicit motives for why they want to engage in prosocial actions and avoid antisocial behavior. A total of 195 children aged 4-12 years were interviewed about their motives for everyday prosocial-moral actions, as well as reported on their relationship with their parents. Children's explicit motives to abstain from antisocial behavior were found to be more external and less other-oriented than their motives for prosocial action. Motives that reflected higher levels of internal motivation became more frequent with age. Moreover, positive parent-child relationships predicted more other-oriented motives and greater explication of moral motives. Overall, the study provides evidence that children's explicit moral motivation is far more heterogeneous than prominent theories of moral development (past and present) suggest.

Learning New Letter-like Writing Patterns Explicitly and Implicitly in Children and Adults.

PubMed

Jongbloed-Pereboom, M; Overvelde, A; Nijhuis-van der Sanden, M W G; Steenbergen, B

2017-12-15

A handwriting task was used to test the assumption that explicit learning is dependent on age and working memory, while implicit learning is not. The effect of age was examined by testing both, typically developing children (5-12 years old, n = 81) and adults (n = 27) in a counterbalanced within-subjects design. Participants were asked to repeatedly write letter-like patterns on a digitizer with a non-inking pen. Reproduction of the pattern was better after explicit learning compared to implicit learning. Age had positive effects on both explicit and implicit learning; working memory did not affect learning in either conditions. These results show that it may be more effective to learn writing new letter-like patterns explicitly and that an explicit teaching method is preferred in mainstream primary education.

Dual methods and approximation concepts in structural synthesis

NASA Technical Reports Server (NTRS)

Fleury, C.; Schmit, L. A., Jr.

1980-01-01

Approximation concepts and dual method algorithms are combined to create a method for minimum weight design of structural systems. Approximation concepts convert the basic mathematical programming statement of the structural synthesis problem into a sequence of explicit primal problems of separable form. These problems are solved by constructing explicit dual functions, which are maximized subject to nonnegativity constraints on the dual variables. It is shown that the joining together of approximation concepts and dual methods can be viewed as a generalized optimality criteria approach. The dual method is successfully extended to deal with pure discrete and mixed continuous-discrete design variable problems. The power of the method presented is illustrated with numerical results for example problems, including a metallic swept wing and a thin delta wing with fiber composite skins.

Core excitation effects on oscillator strengths for transitions in four electron atomic systems

NASA Astrophysics Data System (ADS)

Chang, T. N.; Luo, Yuxiang

2007-06-01

By including explicitly the electronic configurations with two and three simultaneously excited electronic orbital, we have extended the BSCI (B-spline based configuration interaction) method [1] to estimate directly the effect of inner shell core excitation to oscillator strengths for transitions in four-electron atomic systems. We will present explicitly the change in oscillator strengths due to core excitations, especially for transitions involving doubly excited states and those with very small oscillator strengths. The length and velocity results are typically in agreement better than 1% or less. [1] Tu-nan Chang, in Many-body Theory of Atomic Structure and Photoionization, edited by T. N. Chang (World Scientific, Singapore, 1993), p. 213-47; and T. N. Chang and T. K. Fang, Elsevier Radiation Physics and Chemistry 70, 173-190 (2004).

Amnesia Associated with Bilateral Hippocampal and Bilateral Basal Ganglia Lesions in Anoxia with Stimulant Use

PubMed Central

Haut, Marc W.; Hogg, Jeffery P.; Marshalek, Patrick J.; Suter, Blair C.; Miller, Liv E.

2017-01-01

We report a case of a 55-year-old man with ischemic lesions of the bilateral hippocampus and bilateral basal ganglia following a myocardial infarction during an episode of multiple drug use with subsequent anoxia requiring resuscitation. He presented for a neuropsychological evaluation with an anterograde amnesia for both explicit and procedural memory. There are two main points to this case, the unique aspects of the bilateral multifocal lesions and the functional, cognitive impact of these lesions. We hypothesize that his rare focal bilateral lesions of both the hippocampus and basal ganglia are a result of anoxia acting in synergy with his stimulant drug use (cocaine and/or 3,4-methylenedioxy-methamphetamine). Second, his unique lesions produced an explicit and implicit/procedural anterograde amnesia. PMID:28228745

Amnesia Associated with Bilateral Hippocampal and Bilateral Basal Ganglia Lesions in Anoxia with Stimulant Use.

PubMed

Haut, Marc W; Hogg, Jeffery P; Marshalek, Patrick J; Suter, Blair C; Miller, Liv E

2017-01-01

We report a case of a 55-year-old man with ischemic lesions of the bilateral hippocampus and bilateral basal ganglia following a myocardial infarction during an episode of multiple drug use with subsequent anoxia requiring resuscitation. He presented for a neuropsychological evaluation with an anterograde amnesia for both explicit and procedural memory. There are two main points to this case, the unique aspects of the bilateral multifocal lesions and the functional, cognitive impact of these lesions. We hypothesize that his rare focal bilateral lesions of both the hippocampus and basal ganglia are a result of anoxia acting in synergy with his stimulant drug use (cocaine and/or 3,4-methylenedioxy-methamphetamine). Second, his unique lesions produced an explicit and implicit/procedural anterograde amnesia.

Torus Knot Polynomials and Susy Wilson Loops

NASA Astrophysics Data System (ADS)

Giasemidis, Georgios; Tierz, Miguel

2014-12-01

We give, using an explicit expression obtained in (Jones V, Ann Math 126:335, 1987), a basic hypergeometric representation of the HOMFLY polynomial of ( n, m) torus knots, and present a number of equivalent expressions, all related by Heine's transformations. Using this result, the symmetry and the leading polynomial at large N are explicit. We show the latter to be the Wilson loop of 2d Yang-Mills theory on the plane. In addition, after taking one winding to infinity, it becomes the Wilson loop in the zero instanton sector of the 2d Yang-Mills theory, which is known to give averages of Wilson loops in = 4 SYM theory. We also give, using matrix models, an interpretation of the HOMFLY polynomial and the corresponding Jones-Rosso representation in terms of q-harmonic oscillators.

Explicit polarization (X-Pol) potential using ab initio molecular orbital theory and density functional theory.

PubMed

Song, Lingchun; Han, Jaebeom; Lin, Yen-lin; Xie, Wangshen; Gao, Jiali

2009-10-29

The explicit polarization (X-Pol) method has been examined using ab initio molecular orbital theory and density functional theory. The X-Pol potential was designed to provide a novel theoretical framework for developing next-generation force fields for biomolecular simulations. Importantly, the X-Pol potential is a general method, which can be employed with any level of electronic structure theory. The present study illustrates the implementation of the X-Pol method using ab initio Hartree-Fock theory and hybrid density functional theory. The computational results are illustrated by considering a set of bimolecular complexes of small organic molecules and ions with water. The computed interaction energies and hydrogen bond geometries are in good accord with CCSD(T) calculations and B3LYP/aug-cc-pVDZ optimizations.

Implicit and explicit selective attention to smoking cues in smokers indexed by brain potentials.

PubMed

Littel, Marianne; Franken, Ingmar H A

2011-04-01

Substance use disorders are characterized by cognitive processing biases, such as automatically detecting and orienting attention towards drug-related stimuli. However, it is unclear how, when and what kind of attention (i.e. implicit, explicit) interacts with the processing of these stimuli. In addition, it is unclear whether smokers are hypersensitive to emotionally significant cues in general or to smoking-related cues in particular. The present event-related potential study aimed to enhance insight in drug-related processing biases by manipulating attention for smoking and other motivationally relevant (emotional) cues in smokers and non-smokers using a visual oddball task. Each of the stimulus categories served as a target (explicit attention; counting) or as a non-target (implicit attention; oddball) category. Compared with non-smokers, smokers' P300 (350-600 ms) was enhanced to smoking pictures under both attentional conditions. P300 amplitude did not differ between groups in response to positive, negative, and neutral cues. It can be concluded from this study that attention manipulation affects the P300 differently in smokers and non-smokers. Smokers display a specific bias to smoking-related cues, and this bias is present during both explicit and implicit attentional processing. Overall, it can be concluded that both explicit and implicit attentional processes appear to play an important role in drug-related processing bias.

A Meta-Analysis Suggests Different Neural Correlates for Implicit and Explicit Learning.

PubMed

Loonis, Roman F; Brincat, Scott L; Antzoulatos, Evan G; Miller, Earl K

2017-10-11

A meta-analysis of non-human primates performing three different tasks (Object-Match, Category-Match, and Category-Saccade associations) revealed signatures of explicit and implicit learning. Performance improved equally following correct and error trials in the Match (explicit) tasks, but it improved more after correct trials in the Saccade (implicit) task, a signature of explicit versus implicit learning. Likewise, error-related negativity, a marker for error processing, was greater in the Match (explicit) tasks. All tasks showed an increase in alpha/beta (10-30 Hz) synchrony after correct choices. However, only the implicit task showed an increase in theta (3-7 Hz) synchrony after correct choices that decreased with learning. In contrast, in the explicit tasks, alpha/beta synchrony increased with learning and decreased thereafter. Our results suggest that explicit versus implicit learning engages different neural mechanisms that rely on different patterns of oscillatory synchrony. Copyright © 2017 Elsevier Inc. All rights reserved.

Explicitly computing geodetic coordinates from Cartesian coordinates

NASA Astrophysics Data System (ADS)

Zeng, Huaien

2013-04-01

This paper presents a new form of quartic equation based on Lagrange's extremum law and a Groebner basis under the constraint that the geodetic height is the shortest distance between a given point and the reference ellipsoid. A very explicit and concise formulae of the quartic equation by Ferrari's line is found, which avoids the need of a good starting guess for iterative methods. A new explicit algorithm is then proposed to compute geodetic coordinates from Cartesian coordinates. The convergence region of the algorithm is investigated and the corresponding correct solution is given. Lastly, the algorithm is validated with numerical experiments.

Iranian Pre-University Student's Retention of Collocations: Implicit Exposure or Explicit Instruction

ERIC Educational Resources Information Center

Gheisari, Nouzar; Yousofi, Nouroldin

2016-01-01

The effectiveness of different teaching methods of collocational expressions in ESL/EFL contexts of education has been a point of debate for more than two decades, with some believing in explicit and the others in implicit instruction of collocations. In this regard, the present study aimed at finding about which kind of instruction is more…

The Perception of Prosodically Ambiguous Intonation Patterns by L2 English Learners and the Effects of Instruction

ERIC Educational Resources Information Center

Gokgoz Kurt, Burcu; Medlin, Julie; Tessarolo, Ashley

2014-01-01

Considering the contradictory research on explicit teaching of suprasegmentals, the present study aims to investigate the effects of explicit instruction of L2 English learners' perception of prosodically ambiguous intonation patterns, as well as the possible effects of reported musical familiarity on intonation acquisition. A control group and a…

The Role of Experience and Discourse in Children's Developing Understanding of Pretend Play Actions

ERIC Educational Resources Information Center

Rakoczy, Hannes; Tomasello, Michael; Striano, Tricia

2006-01-01

The present work investigated the development of an explicit understanding of pretend play actions. Study 1 revealed a long decalage between earlier implicit understanding of pretence as an intentional activity and a later more explicit understanding. Study 2 was a training study. It tested for two factors--systematic pretence experience and…

The Effects of Explicit Instruction of Formulaic Sequences on Second-Language Writers

ERIC Educational Resources Information Center

Colovic-Markovic, Jelena

2012-01-01

The present study investigated the effects of the explicit teaching of formulaic sequences (i.e., academic and topic-induced) on L2 writing. The research examined separately the effects of the treatment on the students' abilities to produce the target formulaic sequences in controlled (i.e., C-tests) and uncontrolled situations (i.e.,…

Reexamining Effects of Form-Focused Instruction on L2 Pronunciation Development: The Role of Explicit Phonetic Information

ERIC Educational Resources Information Center

Saito, Kazuya

2013-01-01

The present study examines whether and to what degree providing explicit phonetic information (EI) at the beginning of form-focused instruction (FFI) on second language pronunciation can enhance the generalizability and magnitude of FFI effectiveness by increasing learners' ability to notice a new phone. Participants were 49 Japanese learners of…

Effective diffusion of confined active Brownian swimmers.

PubMed

Sandoval, Mario; Dagdug, Leornardo

2014-12-01

We theoretically find the effect of confinement and thermal fluctuations on the diffusivity of a spherical active swimmer moving inside a two-dimensional narrow cavity of general shape. The explicit formulas for the effective diffusion coefficient of a swimmer moving inside two particular cavities are presented. We also compare our analytical results with Brownian dynamics simulations and we obtain excellent agreement.

Measuring Educational Efficiency at Student Level with Parametric Stochastic Distance Functions: An Application to Spanish PISA Results

ERIC Educational Resources Information Center

Perelman, Sergio; Santin, Daniel

2011-01-01

The aim of the present paper is to examine the observed differences in Students' test performance across public and private-voucher schools in Spain. For this purpose, we explicitly consider that education is a multi-input multi-output production process subject to inefficient behaviors, which can be identified at student level using a parametric…

Convergence acceleration of viscous flow computations

NASA Technical Reports Server (NTRS)

Johnson, G. M.

1982-01-01

A multiple-grid convergence acceleration technique introduced for application to the solution of the Euler equations by means of Lax-Wendroff algorithms is extended to treat compressible viscous flow. Computational results are presented for the solution of the thin-layer version of the Navier-Stokes equations using the explicit MacCormack algorithm, accelerated by a convective coarse-grid scheme. Extensions and generalizations are mentioned.

Children's Agency in Creating and Maintaining Language Policy in Practice in Two "Language Profile" Preschools in Sweden

ERIC Educational Resources Information Center

Boyd, Sally; Huss, Leena; Ottesjö, Cajsa

2017-01-01

This paper presents results from an ethnographic study of language policy as it is enacted in everyday interaction in two language profile preschools in Sweden with explicit monolingual language policies: English and Finnish, respectively. However, in both preschools, children are free to choose language or code alternate. The study shows how…

False memories and lexical decision: even twelve primes do not cause long-term semantic priming.

PubMed

Zeelenberg, René; Pecher, Diane

2002-03-01

Semantic priming effects are usually obtained only if the prime is presented shortly before the target stimulus. Recent evidence obtained with the so-called false memory paradigm suggests, however, that in both explicit and implicit memory tasks semantic relations between words can result in long-lasting effects when multiple 'primes' are presented. The aim of the present study was to investigate whether these effects would generalize to lexical decision. In four experiments we showed that even as many as 12 primes do not cause long-term semantic priming. In all experiments, however, a repetition priming effect was obtained. The present results are consistent with a number of other results showing that semantic information plays a minimal role in long-term priming in visual word recognition.

Numerical study of the flow in a three-dimensional thermally driven cavity

NASA Astrophysics Data System (ADS)

Rauwoens, Pieter; Vierendeels, Jan; Merci, Bart

2008-06-01

Solutions for the fully compressible Navier-Stokes equations are presented for the flow and temperature fields in a cubic cavity with large horizontal temperature differences. The ideal-gas approximation for air is assumed and viscosity is computed using Sutherland's law. The three-dimensional case forms an extension of previous studies performed on a two-dimensional square cavity. The influence of imposed boundary conditions in the third dimension is investigated as a numerical experiment. Comparison is made between convergence rates in case of periodic and free-slip boundary conditions. Results with no-slip boundary conditions are presented as well. The effect of the Rayleigh number is studied. Results are computed using a finite volume method on a structured, collocated grid. An explicit third-order discretization for the convective part and an implicit central discretization for the acoustic part and for the diffusive part are used. To stabilize the scheme an artificial dissipation term for the pressure and the temperature is introduced. The discrete equations are solved using a time-marching method with restrictions on the timestep corresponding to the explicit parts of the solver. Multigrid is used as acceleration technique.

Implicit and Explicit Theory of Mind Reasoning in Autism Spectrum Disorders: The Impact of Experience

ERIC Educational Resources Information Center

Schuwerk, Tobias; Vuori, Maria; Sodian, Beate

2015-01-01

This study aimed to investigate the relationship between explicit and implicit forms of Theory of Mind reasoning and to test the influence of experience on implicit Theory of Mind reasoning in individuals with autism spectrum disorders and in neurotypical adults. Results from two standard explicit Theory of Mind tasks are mixed: Individuals with…

Implicit and explicit processing in deep dyslexia: Semantic blocking as a test for failure of inhibition in the phonological output lexicon.

PubMed

Colangelo, Annette; Buchanan, Lori

2006-12-01

The failure of inhibition hypothesis posits a theoretical distinction between implicit and explicit access in deep dyslexia. Specifically, the effects of failure of inhibition are assumed only in conditions that have an explicit selection requirement in the context of production (i.e., aloud reading). In contrast, the failure of inhibition hypothesis proposes that implicit processing and explicit access to semantic information without production demands are intact in deep dyslexia. Evidence for intact implicit and explicit access requires that performance in deep dyslexia parallels that observed in neurologically intact participants on tasks based on implicit and explicit processes. In other words, deep dyslexics should produce normal effects in conditions with implicit task demands (i.e., lexical decision) and on tasks based on explicit access without production (i.e., forced choice semantic decisions) because failure of inhibition does not impact the availability of lexical information, only explicit retrieval in the context of production. This research examined the distinction between implicit and explicit processes in deep dyslexia using semantic blocking in lexical decision and forced choice semantic decisions as a test for the failure of inhibition hypothesis. The results of the semantic blocking paradigm support the distinction between implicit and explicit processing and provide evidence for failure of inhibition as an explanation for semantic errors in deep dyslexia.

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. © 2013.

Self-Love or Other-Love? Explicit Other-Preference but Implicit Self-Preference

PubMed Central

Gebauer, Jochen E.; Göritz, Anja S.; Hofmann, Wilhelm; Sedikides, Constantine

2012-01-01

Do humans prefer the self even over their favorite other person? This question has pervaded philosophy and social-behavioral sciences. Psychology’s distinction between explicit and implicit preferences calls for a two-tiered solution. Our evolutionarily-based Dissociative Self-Preference Model offers two hypotheses. Other-preferences prevail at an explicit level, because they convey caring for others, which strengthens interpersonal bonds–a major evolutionary advantage. Self-preferences, however, prevail at an implicit level, because they facilitate self-serving automatic behavior, which favors the self in life-or-die situations–also a major evolutionary advantage. We examined the data of 1,519 participants, who completed an explicit measure and one of five implicit measures of preferences for self versus favorite other. The results were consistent with the Dissociative Self-Preference Model. Explicitly, participants preferred their favorite other over the self. Implicitly, however, they preferred the self over their favorite other (be it their child, romantic partner, or best friend). Results are discussed in relation to evolutionary theorizing on self-deception. PMID:22848605

Comment on ``Nonlinear gyrokinetic theory with polarization drift'' [Phys. Plasmas 17, 082304 (2010)

NASA Astrophysics Data System (ADS)

Leerink, S.; Parra, F. I.; Heikkinen, J. A.

2010-12-01

In this comment, we show that by using the discrete particle distribution function the changes of the phase-space volume of gyrocenter coordinates due to the fluctuating E ×B velocity do not explicitly appear in the Poisson equation and the [Sosenko et al., Phys. Scr. 64, 264 (2001)] result is recovered. It is demonstrated that there is no contradiction between the work presented by Sosenko et al. and the work presented by [Wang et al., Phys. Plasmas 17, 082304 (2010)].

General form of genuine multipartite entanglement quantum channels for teleportation

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

Chen Pingxing; Key Laboratory of Quantum Communication and Quantum Computation, University of Science and Technology of China, Hefei 230026; Department of Physics, National University of Defense Technology, Changsha 410073

2006-09-15

Recently Yeo and Chua [Phys. Rev. Lett. 96, 060502 (2006)] presented an explicit protocol for faithfully teleporting an arbitrary two-qubit state via a genuine four-qubit entanglement channel. Here we generalize completely their results to teleporting an arbitrary N-qubit state via genuine N-qubit entanglement channels. And we present the general form of the genuine multipartite entanglement channels, namely, the sufficient and necessary condition the genuine N-qubit entanglement channels must satisfy to teleport an arbitrary N-qubit state.

Entropy of gaseous boron monobromide

NASA Astrophysics Data System (ADS)

Wang, Jian-Feng; Peng, Xiao-Long; Zhang, Lie-Hui; Wang, Chao-Wen; Jia, Chun-Sheng

2017-10-01

We present an explicit representation of molar entropy for gaseous boron monobromide in terms of experimental values of only three molecular constants. Fortunately, through comparison of theoretically calculated results and experimental data, we find that the molar entropy of gaseous boron monobromide can be well predicted by employing the improved Manning-Rosen oscillator to describe the internal vibration of boron monobromide molecule. The present approach provides also opportunities for theoretical predictions of molar entropy for other gases with no use of large amounts of experimental spectroscopy data.

Creep-Rupture Data Analysis - Engineering Application of Regression Techniques. Ph.D. Thesis - North Carolina State Univ.

NASA Technical Reports Server (NTRS)

Rummler, D. R.

1976-01-01

The results are presented of investigations to apply regression techniques to the development of methodology for creep-rupture data analysis. Regression analysis techniques are applied to the explicit description of the creep behavior of materials for space shuttle thermal protection systems. A regression analysis technique is compared with five parametric methods for analyzing three simulated and twenty real data sets, and a computer program for the evaluation of creep-rupture data is presented.

Sending Nudes: Sex, Self-Rated Mate Value, and Trait Machiavellianism Predict Sending Unsolicited Explicit Images

PubMed Central

March, Evita; Wagstaff, Danielle L.

2017-01-01

Modern dating platforms have given rise to new dating and sexual behaviors. In the current study, we examine predictors of sending unsolicited explicit images, a particularly underexplored online sexual behavior. The aim of the current study was to explore the utility of dark personality traits (i.e., narcissism, Machiavellianism, psychopathy, and sadism) and self-rated mate value in predicting attitudes toward and behavior of sending unsolicited explicit images. Two hundred and forty participants (72% female; Mage = 25.96, SD = 9.79) completed an online questionnaire which included a measure of self-rated mate value, a measure of dark personality traits, and questions regarding sending unsolicited explicit images (operationalized as the explicit image scale). Men, compared to women, were found to have higher explicit image scale scores, and both self-rated mate value and trait Machiavellianism were positive predictors of explicit image scale scores. Interestingly, there were no significant interactions between sex and these variables. Further, Machiavellianism mediated all relationships between other dark traits and explicit image scale scores, indicating this behavior is best explained by the personality trait associated with behavioral strategies. In sum, these results provide support for the premise that sending unsolicited explicit images may be a tactic of a short-term mating strategy; however, future research should further explore this claim. PMID:29326632

Effects of explicit instruction on the acquisition of students' science inquiry skills in grades 5 and 6 of primary education

NASA Astrophysics Data System (ADS)

Kruit, P. M.; Oostdam, R. J.; van den Berg, E.; Schuitema, J. A.

2018-03-01

In most primary science classes, students are taught science inquiry skills by way of learning by doing. Research shows that explicit instruction may be more effective. The aim of this study was to investigate the effects of explicit instruction on the acquisition of inquiry skills. Participants included 705 Dutch fifth and sixth graders. Students in an explicit instruction condition received an eight-week intervention of explicit instruction on inquiry skills. In the lessons of the implicit condition, all aspects of explicit instruction were absent. Students in the baseline condition followed their regular science curriculum. In a quasi-experimental pre-test-post-test design, two paper-and-pencil tests and three performance assessments were used to examine the acquisition and transfer of inquiry skills. Additionally, questionnaires were used to measure metacognitive skills. The results of a multilevel analysis controlling for pre-tests, general cognitive ability, age, gender and grade level indicated that explicit instruction facilitates the acquisition of science inquiry skills. Specifically on the performance assessment with an unfamiliar topic, students in the explicit condition outperformed students of both the implicit and baseline condition. Therefore, this study provides a strong argument for including an explicit teaching method for developing inquiry skills in primary science education.

The influence of sexually explicit online media on sex: do men who have sex with men believe they "do what they see"?

PubMed

Nelson, Kimberly M; Leickly, Emily; Yang, Joyce P; Pereira, Andrew; Simoni, Jane M

2014-01-01

Over the past two decades, men who have sex with men (MSM) have engaged in increasing consumption of MSM-specific sexually explicit online media (i.e., online pornography). Furthermore, the amount of MSM-specific sexually explicit online media portraying unprotected anal intercourse (UAI) has increased, raising concerns about HIV transmission among the actors and the potential encouragement of risky sex among consumers. The influence of sexually explicit online media on sexual risk-taking, at present largely understudied, could lead to new avenues for innovative HIV-prevention strategies targeting at-risk MSM. In this preliminary assessment, in-depth qualitative interviews were conducted with 16 MSM in the Seattle area to elucidate MSM's perceptions about the influence of sexually explicit online media on their own and other MSM's sexual behaviors. Participants reported that sexually explicit online media: (1) plays an educational role, (2) increases comfort with sexuality, and (3) sets expectations about sexual behaviors. While participants overwhelmingly reported not feeling personally influenced by viewing UAI in sexually explicit online media, they believed viewing UAI increased sexual risk-taking among other MSM. Specifically, participants reported that the high prevalence of UAI in sexually explicit online media sends the message, at least to other MSM, that (1) engaging in UAI is common, (2) UAI is acceptable and "ok" to engage in, and (3) future partners will desire or expect UAI. Overall, this preliminary assessment indicates that sexually explicit online media exposure may have both positive (e.g., helping MSM become more comfortable with their sexuality) and negative (e.g., normalizing UAI) impacts on the sexual health of MSM and may be useful in the development of novel HIV-prevention interventions.

Moderators of Implicit-Explicit Exercise Cognition Concordance.

PubMed

Berry, Tanya R; Rodgers, Wendy M; Markland, David; Hall, Craig R

2016-12-01

Investigating implicit-explicit concordance can aid in understanding underlying mechanisms and possible intervention effects. This research examined the concordance between implicit associations of exercise with health or appearance and related explicit motives. Variables considered as possible moderators were behavioral regulations, explicit attitudes, and social desirability. Participants (N = 454) completed measures of implicit associations of exercise with health and appearance and questionnaire measures of health and appearance motives, attitudes, social desirability, and behavioral regulations. Attitudes significantly moderated the relationship between implicit associations of exercise with health and health motives. Identified regulations significantly moderated implicit-explicit concordance with respect to associations with appearance. These results suggest that implicit and explicit exercise-related cognitions are not necessarily independent and their relationship to each other may be moderated by attitudes or some forms of behavioral regulation. Future research that takes a dual-processing approach to exercise behavior should consider potential theoretical moderators of concordance.

The nature of declarative and nondeclarative knowledge for implicit and explicit learning.

PubMed

Kirkhart, M W

2001-10-01

Using traditional implicit and explicit artificial-grammar learning tasks, the author investigated the similarities and differences between the acquisition of declarative knowledge under implicit and explicit learning conditions and the functions of the declarative knowledge during testing. Results suggested that declarative knowledge was not predictive of or required for implicit learning but was related to consistency in implicit learning performance. In contrast, declarative knowledge was predictive of and required for explicit learning and was related to consistency in performance. For explicit learning, the declarative knowledge functioned as a guide for other behavior. In contrast, for implicit learning, the declarative knowledge did not serve as a guide for behavior but was instead a post hoc description of the most commonly seen stimuli.

Helicopter time-domain electromagnetic numerical simulation based on Leapfrog ADI-FDTD

NASA Astrophysics Data System (ADS)

Guan, S.; Ji, Y.; Li, D.; Wu, Y.; Wang, A.

2017-12-01

We present a three-dimension (3D) Alternative Direction Implicit Finite-Difference Time-Domain (Leapfrog ADI-FDTD) method for the simulation of helicopter time-domain electromagnetic (HTEM) detection. This method is different from the traditional explicit FDTD, or ADI-FDTD. Comparing with the explicit FDTD, leapfrog ADI-FDTD algorithm is no longer limited by Courant-Friedrichs-Lewy(CFL) condition. Thus, the time step is longer. Comparing with the ADI-FDTD, we reduce the equations from 12 to 6 and .the Leapfrog ADI-FDTD method will be easier for the general simulation. First, we determine initial conditions which are adopted from the existing method presented by Wang and Tripp(1993). Second, we derive Maxwell equation using a new finite difference equation by Leapfrog ADI-FDTD method. The purpose is to eliminate sub-time step and retain unconditional stability characteristics. Third, we add the convolution perfectly matched layer (CPML) absorbing boundary condition into the leapfrog ADI-FDTD simulation and study the absorbing effect of different parameters. Different absorbing parameters will affect the absorbing ability. We find the suitable parameters after many numerical experiments. Fourth, We compare the response with the 1-Dnumerical result method for a homogeneous half-space to verify the correctness of our algorithm.When the model contains 107*107*53 grid points, the conductivity is 0.05S/m. The results show that Leapfrog ADI-FDTD need less simulation time and computer storage space, compared with ADI-FDTD. The calculation speed decreases nearly four times, memory occupation decreases about 32.53%. Thus, this algorithm is more efficient than the conventional ADI-FDTD method for HTEM detection, and is more precise than that of explicit FDTD in the late time.

Mimetic discretization of the Abelian Chern-Simons theory and link invariants

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

Di Bartolo, Cayetano; Grau, Javier; Leal, Lorenzo

A mimetic discretization of the Abelian Chern-Simons theory is presented. The study relies on the formulation of a theory of differential forms in the lattice, including a consistent definition of the Hodge duality operation. Explicit expressions for the Gauss Linking Number in the lattice, which correspond to their continuum counterparts are given. A discussion of the discretization of metric structures in the space of transverse vector densities is presented. The study of these metrics could serve to obtain explicit formulae for knot an link invariants in the lattice.

Mimetic discretization of the Abelian Chern-Simons theory and link invariants

NASA Astrophysics Data System (ADS)

Di Bartolo, Cayetano; Grau, Javier; Leal, Lorenzo

2013-12-01

A mimetic discretization of the Abelian Chern-Simons theory is presented. The study relies on the formulation of a theory of differential forms in the lattice, including a consistent definition of the Hodge duality operation. Explicit expressions for the Gauss Linking Number in the lattice, which correspond to their continuum counterparts are given. A discussion of the discretization of metric structures in the space of transverse vector densities is presented. The study of these metrics could serve to obtain explicit formulae for knot an link invariants in the lattice.

The Association Between Implicit and Explicit Attitudes Toward Smoking and Support for Tobacco Control Measures

PubMed Central

Chassin, Laurie; Presson, Clark C.

2013-01-01

Introduction: This study examined the association between implicit and explicit attitudes toward smoking and support for tobacco control policies. Methods: Participants were from an ongoing longitudinal study of the natural history of smoking who also completed a web-based assessment of implicit attitudes toward smoking (N = 1,337). Multiple regression was used to test the association between covariates (sex, age, educational attainment, parent status, and smoking status), implicit attitude toward smoking, and explicit attitude toward smoking and support for tobacco control policies. The moderating effect of the covariates on the relation between attitudes and support for policies was also tested. Results: Females, those with higher educational attainment, parents, and nonsmokers expressed more support for tobacco control policy measures. For nonsmokers, only explicit attitude was significantly associated with support for policies. For smokers, both explicit and implicit attitudes were significantly associated with support. The effect of explicit attitude was stronger for those with lower educational attainment. Conclusions: Both explicit and implicit smoking attitudes are important for building support for tobacco control policies, particularly among smokers. More research is needed on how to influence explicit and implicit attitudes to inform policy advocacy campaigns. PMID:22581941

Velocity Gradient Power Functional for Brownian Dynamics.

PubMed

de Las Heras, Daniel; Schmidt, Matthias

2018-01-12

We present an explicit and simple approximation for the superadiabatic excess (over ideal gas) free power functional, admitting the study of the nonequilibrium dynamics of overdamped Brownian many-body systems. The functional depends on the local velocity gradient and is systematically obtained from treating the microscopic stress distribution as a conjugate field. The resulting superadiabatic forces are beyond dynamical density functional theory and are of a viscous nature. Their high accuracy is demonstrated by comparison to simulation results.

Velocity Gradient Power Functional for Brownian Dynamics

NASA Astrophysics Data System (ADS)

de las Heras, Daniel; Schmidt, Matthias

2018-01-01

We present an explicit and simple approximation for the superadiabatic excess (over ideal gas) free power functional, admitting the study of the nonequilibrium dynamics of overdamped Brownian many-body systems. The functional depends on the local velocity gradient and is systematically obtained from treating the microscopic stress distribution as a conjugate field. The resulting superadiabatic forces are beyond dynamical density functional theory and are of a viscous nature. Their high accuracy is demonstrated by comparison to simulation results.

The Sensorimotor System Can Sculpt Behaviorally Relevant Representations for Motor Learning

PubMed Central

2016-01-01

Abstract The coordinate system in which humans learn novel motor skills is controversial. The representation of sensorimotor skills has been extensively studied by examining generalization after learning perturbations specifically designed to be ambiguous as to their coordinate system. Recent studies have found that learning is not represented in any simple coordinate system and can potentially be accounted for by a mixed representation. Here, instead of probing generalization, which has led to conflicting results, we examine whether novel dynamics can be learned when explicitly and unambiguously presented in particular coordinate systems. Subjects performed center–out reaches to targets in the presence of a force field, while varying the orientation of their hand (i.e., the wrist angle) across trials. Different groups of subjects experienced force fields that were explicitly presented either in Cartesian coordinates (field independent of hand orientation), in object coordinates (field rotated with hand orientation), or in anti-object coordinates (field rotated counter to hand orientation). Subjects learned to represent the dynamics when presented in either Cartesian or object coordinates, learning these as well as an ambiguous force field. However, learning was slower for the object-based dynamics and substantially impaired for the anti-object presentation. Our results show that the motor system is able to tune its representation to at least two natural coordinate systems but is impaired when the representation of the task does not correspond to a behaviorally relevant coordinate system. Our results show that the motor system can sculpt its representation through experience to match those of natural tasks. PMID:27588304

Children's Implicit and Explicit Ethnic Group Attitudes, Ethnic Group Identification, and Self-Esteem

ERIC Educational Resources Information Center

Davis, Stephanie C.; Leman, Patrick J.; Barrett, Martyn

2007-01-01

An increasing amount of research explores how children distinguish different aspects of ethnic group attitudes. However, little work has focused on how these aspects tie in with other social and psychological processes. In the present study, 112 black and white children aged 5-, 7- and 9-years completed tests of implicit and explicit ethnic group…

Impact of Explicit Vocabulary Instruction on Writing Achievement of Upper-Intermediate EFL Learners

ERIC Educational Resources Information Center

Solati-Dehkordi, Seyed Amir; Salehi, Hadi

2016-01-01

Studying explicit vocabulary instruction effects on improving L2 learners' writing skill and their short and long-term retention is the purpose of the present study. To achieve the mentioned goal, a fill-in-the-blank test including 36 single words and 60 lexical phrases were administrated to 30 female upper-intermediate EFL learners. The EFL…

A Non-Blaming Chance and Action Approach to Therapy with Sexually Explicit Media Overuse: A Case Study

ERIC Educational Resources Information Center

Wernik, Uri

2012-01-01

In this clinical presentation a non-blaming, non-judgmental approach to overuse of sexually explicit media (SEM) is introduced. This approach normalizes the problem and sees it in the context of evolution and market forces. It is claimed that such an approach contributes to change and strengthens the therapeutic alliance. A new technique utilizing…

Improving Readability in an Explicit Genre-Based Approach: The Case of an EFL Workplace Context

ERIC Educational Resources Information Center

Albino, Gabriel

2017-01-01

The present study investigates how learners of English as a foreign language (EFL) improve the readability of their texts in an explicit genre-based approach that is utilized in an oil and gas exploration workplace in Angola. By drawing on the English for Specific Purposes and Systemic Functional Linguistics genre traditions, the study engages 18…

A numerical algorithm for the explicit calculation of SU(N) and SL(N,C) Clebsch-Gordan coefficients

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

Alex, Arne; Delft, Jan von; Kalus, Matthias

2011-02-15

We present an algorithm for the explicit numerical calculation of SU(N) and SL(N,C) Clebsch-Gordan coefficients, based on the Gelfand-Tsetlin pattern calculus. Our algorithm is well suited for numerical implementation; we include a computer code in an appendix. Our exposition presumes only familiarity with the representation theory of SU(2).

Making Grammar Explicit in the Classroom: An Illustration Using the Spanish Subjunctive.

ERIC Educational Resources Information Center

Kilroe, Patricia

1988-01-01

It is proposed that explicit explanations of grammar concepts in the first language can be useful in teaching the related structures in a second language. The example used is that of the subjunctive mood, taught first in English and then in Spanish. Specific procedures for presenting the concept in English are outlined, including a set of…

Flory-type theories of polymer chains under different external stimuli

NASA Astrophysics Data System (ADS)

Budkov, Yu A.; Kiselev, M. G.

2018-01-01

In this Review, we present a critical analysis of various applications of the Flory-type theories to a theoretical description of the conformational behavior of single polymer chains in dilute polymer solutions under a few external stimuli. Different theoretical models of flexible polymer chains in the supercritical fluid are discussed and analysed. Different points of view on the conformational behavior of the polymer chain near the liquid-gas transition critical point of the solvent are presented. A theoretical description of the co-solvent-induced coil-globule transitions within the implicit-solvent-explicit-co-solvent models is discussed. Several explicit-solvent-explicit-co-solvent theoretical models of the coil-to-globule-to-coil transition of the polymer chain in a mixture of good solvents (co-nonsolvency) are analysed and compared with each other. Finally, a new theoretical model of the conformational behavior of the dielectric polymer chain under the external constant electric field in the dilute polymer solution with an explicit account for the many-body dipole correlations is discussed. The polymer chain collapse induced by many-body dipole correlations of monomers in the context of statistical thermodynamics of dielectric polymers is analysed.

Regulatory T cell effects in antitumor laser immunotherapy: a mathematical model and analysis

NASA Astrophysics Data System (ADS)

Dawkins, Bryan A.; Laverty, Sean M.

2016-03-01

Regulatory T cells (Tregs) have tremendous influence on treatment outcomes in patients receiving immunotherapy for cancerous tumors. We present a mathematical model incorporating the primary cellular and molecular components of antitumor laser immunotherapy. We explicitly model developmental classes of dendritic cells (DCs), cytotoxic T cells (CTLs), primary and metastatic tumor cells, and tumor antigen. Regulatory T cells have been shown to kill antigen presenting cells, to influence dendritic cell maturation and migration, to kill activated killer CTLs in the tumor microenvironment, and to influence CTL proliferation. Since Tregs affect explicitly modeled cells, but we do not explicitly model dynamics of Treg themselves, we use model parameters to analyze effects of Treg immunosuppressive activity. We will outline a systematic method for assigning clinical outcomes to model simulations and use this condition to associate simulated patient treatment outcome with Treg activity.

LEAP into the Pfizer Global Virtual Library (PGVL) space: creation of readily synthesizable design ideas automatically.

PubMed

Hu, Qiyue; Peng, Zhengwei; Kostrowicki, Jaroslav; Kuki, Atsuo

2011-01-01

Pfizer Global Virtual Library (PGVL) of 10(13) readily synthesizable molecules offers a tremendous opportunity for lead optimization and scaffold hopping in drug discovery projects. However, mining into a chemical space of this size presents a challenge for the concomitant design informatics due to the fact that standard molecular similarity searches against a collection of explicit molecules cannot be utilized, since no chemical information system could create and manage more than 10(8) explicit molecules. Nevertheless, by accepting a tolerable level of false negatives in search results, we were able to bypass the need for full 10(13) enumeration and enabled the efficient similarity search and retrieval into this huge chemical space for practical usage by medicinal chemists. In this report, two search methods (LEAP1 and LEAP2) are presented. The first method uses PGVL reaction knowledge to disassemble the incoming search query molecule into a set of reactants and then uses reactant-level similarities into actual available starting materials to focus on a much smaller sub-region of the full virtual library compound space. This sub-region is then explicitly enumerated and searched via a standard similarity method using the original query molecule. The second method uses a fuzzy mapping onto candidate reactions and does not require exact disassembly of the incoming query molecule. Instead Basis Products (or capped reactants) are mapped into the query molecule and the resultant asymmetric similarity scores are used to prioritize the corresponding reactions and reactant sets. All sets of Basis Products are inherently indexed to specific reactions and specific starting materials. This again allows focusing on a much smaller sub-region for explicit enumeration and subsequent standard product-level similarity search. A set of validation studies were conducted. The results have shown that the level of false negatives for the disassembly-based method is acceptable when the query molecule can be recognized for exact disassembly, and the fuzzy reaction mapping method based on Basis Products has an even better performance in terms of lower false-negative rate because it is not limited by the requirement that the query molecule needs to be recognized by any disassembly algorithm. Both search methods have been implemented and accessed through a powerful desktop molecular design tool (see ref. (33) for details). The chapter will end with a comparison of published search methods against large virtual chemical space.

Mapping malaria risk and vulnerability in the United Republic of Tanzania: a spatial explicit model.

PubMed

Hagenlocher, Michael; Castro, Marcia C

2015-01-01

Outbreaks of vector-borne diseases (VBDs) impose a heavy burden on vulnerable populations. Despite recent progress in eradication and control, malaria remains the most prevalent VBD. Integrative approaches that take into account environmental, socioeconomic, demographic, biological, cultural, and political factors contributing to malaria risk and vulnerability are needed to effectively reduce malaria burden. Although the focus on malaria risk has increasingly gained ground, little emphasis has been given to develop quantitative methods for assessing malaria risk including malaria vulnerability in a spatial explicit manner. Building on a conceptual risk and vulnerability framework, we propose a spatial explicit approach for modeling relative levels of malaria risk - as a function of hazard, exposure, and vulnerability - in the United Republic of Tanzania. A logistic regression model was employed to identify a final set of risk factors and their contribution to malaria endemicity based on multidisciplinary geospatial information. We utilized a Geographic Information System for the construction and visualization of a malaria vulnerability index and its integration into a spatially explicit malaria risk map. The spatial pattern of malaria risk was very heterogeneous across the country. Malaria risk was higher in Mainland areas than in Zanzibar, which is a result of differences in both malaria entomological inoculation rate and prevailing vulnerabilities. Areas of high malaria risk were identified in the southeastern part of the country, as well as in two distinct "hotspots" in the northwestern part of the country bordering Lake Victoria, while concentrations of high malaria vulnerability seem to occur in the northwestern, western, and southeastern parts of the mainland. Results were visualized using both 10×10 km(2) grids and subnational administrative units. The presented approach makes an important contribution toward a decision support tool. By decomposing malaria risk into its components, the approach offers evidence on which factors could be targeted for reducing malaria risk and vulnerability to the disease. Ultimately, results offer relevant information for place-based intervention planning and more effective spatial allocation of resources.

Differential Classical Conditioning of the Nocebo Effect: Increasing Heat-Pain Perception without Verbal Suggestions

PubMed Central

Bräscher, Anne-Kathrin; Kleinböhl, Dieter; Hölzl, Rupert; Becker, Susanne

2017-01-01

Background: Nocebo effects, including nocebo hyperalgesia, are a common phenomenon in clinical routine with manifold negative consequences. Both explicit expectations and learning by conditioning are known to induce nocebo effects, but the specific role of conditioning remains unclear, because conditioning is rarely implemented independent of verbal suggestions. Further, although pain is a multidimensional phenomenon, nocebo effects are usually assessed in subjective ratings only, neglecting, e.g., behavioral aspects. The aim of this study was to test whether nocebo hyperalgesia can be learned by conditioning without explicit expectations, to assess nocebo effects in different response channels, and to exploratively assess, whether contingency awareness is a necessary condition for conditioned nocebo hyperalgesia. Methods: Twenty-one healthy volunteers were classically conditioned using painful and non-painful heat stimuli that followed two different cues. The conditioned nocebo effect was assessed by subjective ratings of perceived stimulation intensity on a visual analog scale and a behavioral discrimination task, assessing sensitization and habituation in response to the same stimulation following the two cues. Results: Results show a conditioned nocebo effect indicated by the subjective intensity ratings. Conditioned effects were also seen in the behavioral responses, but paradoxically, behavioral responses indicated decreased perception after conditioning, but only for subjects successfully conditioned as indicated by the subjective ratings. Explorative analyses suggested that awareness of the contingencies and the different cues was not necessary for successful conditioning. Conclusion: Nocebo effects can be learned without inducing additional explicit expectations. The dissociation between the two response channels, possibly representing the conditioned and a compensatory response, highlights the importance of considering different outcomes in nocebo responses to fully understand underlying mechanisms. The present results challenge the role of explicit expectations in conditioned nocebo effects and are relevant with implications in clinical contexts, e.g., when transient adverse effects become conditioned. PMID:29321752

An implicit dispersive transport algorithm for the US Geological Survey MOC3D solute-transport model

USGS Publications Warehouse

Kipp, K.L.; Konikow, Leonard F.; Hornberger, G.Z.

1998-01-01

This report documents an extension to the U.S. Geological Survey MOC3D transport model that incorporates an implicit-in-time difference approximation for the dispersive transport equation, including source/sink terms. The original MOC3D transport model (Version 1) uses the method of characteristics to solve the transport equation on the basis of the velocity field. The original MOC3D solution algorithm incorporates particle tracking to represent advective processes and an explicit finite-difference formulation to calculate dispersive fluxes. The new implicit procedure eliminates several stability criteria required for the previous explicit formulation. This allows much larger transport time increments to be used in dispersion-dominated problems. The decoupling of advective and dispersive transport in MOC3D, however, is unchanged. With the implicit extension, the MOC3D model is upgraded to Version 2. A description of the numerical method of the implicit dispersion calculation, the data-input requirements and output options, and the results of simulator testing and evaluation are presented. Version 2 of MOC3D was evaluated for the same set of problems used for verification of Version 1. These test results indicate that the implicit calculation of Version 2 matches the accuracy of Version 1, yet is more efficient than the explicit calculation for transport problems that are characterized by a grid Peclet number less than about 1.0.

The numerology of gender: gendered perceptions of even and odd numbers

PubMed Central

Wilkie, James E. B.; Bodenhausen, Galen V.

2015-01-01

Do numbers have gender? Wilkie and Bodenhausen (2012) examined this issue in a series of experiments on perceived gender. They examined the perceived gender of baby faces and foreign names. Arbitrary numbers presented with these faces and names influenced their perceived gender. Specifically, odd numbers connoted masculinity, while even numbers connoted femininity. In two new studies (total N = 315), we further examined the gendering of numbers. The first study examined explicit ratings of 1-digit numbers. We confirmed that odd numbers seemed masculine while even numbers seemed feminine. Although both men and women showed this pattern, it was more pronounced among women. We also examined whether this pattern holds for automatic as well as deliberated reactions. Results of an Implicit Association Test showed that it did, but only among the women. The implicit and explicit patterns of numerical gender ascription were moderately correlated. The second study examined explicit perceptions of 2-digit numbers. Again, women viewed odd numbers as more masculine and less feminine than even numbers. However, men viewed 2-digit numbers as relatively masculine, regardless of whether they were even or odd. These results indicate that women and men impute gender to numbers in different ways and to different extents. We discuss possible implications for understanding how people relate to and are influenced by numbers in a variety of real-life contexts. PMID:26113839

Children’s belief- and desire-reasoning in the temporoparietal junction: evidence for specialization from functional near-infrared spectroscopy

PubMed Central

Bowman, Lindsay C.; Kovelman, Ioulia; Hu, Xiaosu; Wellman, Henry M.

2015-01-01

Behaviorally, children’s explicit theory of mind (ToM) proceeds in a progression of mental-state understandings: developmentally, children demonstrate accurate explicit desire-reasoning before accurate explicit belief-reasoning. Given its robust and cross-cultural nature, we hypothesize this progression may be paced in part by maturation/specialization of the brain. Neuroimaging research demonstrates that the right temporoparietal junction (TPJ) becomes increasingly selective for ToM reasoning as children age, and as their ToM improves. But this research has narrowly focused on beliefs or on undifferentiated mental-states. A recent ERP study in children included a critical contrast to desire-reasoning, and demonstrated that right posterior potentials differentiated belief-reasoning from desire-reasoning. Taken together, the literature suggests that children’s desire-belief progression may be paced by specialization of the right TPJ for belief-reasoning specifically, beyond desire-reasoning. In the present study, we tested this hypothesis directly by examining children’s belief- and desire-reasoning using functional near-infrared spectroscopy in conjunction with structural magnetic resonance imaging to pinpoint brain activation in the right TPJ. Results showed greatest activation in the right TPJ for belief-reasoning, beyond desire-reasoning, and beyond non-mental reasoning (control). Findings replicate and critically extend prior ERP results, and provide clear evidence for a specific neural mechanism underlying children’s progression from understanding desires to understanding beliefs. PMID:26500527

The numerology of gender: gendered perceptions of even and odd numbers.

PubMed

Wilkie, James E B; Bodenhausen, Galen V

2015-01-01

Do numbers have gender? Wilkie and Bodenhausen (2012) examined this issue in a series of experiments on perceived gender. They examined the perceived gender of baby faces and foreign names. Arbitrary numbers presented with these faces and names influenced their perceived gender. Specifically, odd numbers connoted masculinity, while even numbers connoted femininity. In two new studies (total N = 315), we further examined the gendering of numbers. The first study examined explicit ratings of 1-digit numbers. We confirmed that odd numbers seemed masculine while even numbers seemed feminine. Although both men and women showed this pattern, it was more pronounced among women. We also examined whether this pattern holds for automatic as well as deliberated reactions. Results of an Implicit Association Test showed that it did, but only among the women. The implicit and explicit patterns of numerical gender ascription were moderately correlated. The second study examined explicit perceptions of 2-digit numbers. Again, women viewed odd numbers as more masculine and less feminine than even numbers. However, men viewed 2-digit numbers as relatively masculine, regardless of whether they were even or odd. These results indicate that women and men impute gender to numbers in different ways and to different extents. We discuss possible implications for understanding how people relate to and are influenced by numbers in a variety of real-life contexts.

An explicitly solvated full atomistic model of the cardiac thin filament and application on the calcium binding affinity effects from familial hypertrophic cardiomyopathy linked mutations

NASA Astrophysics Data System (ADS)

Williams, Michael; Schwartz, Steven

2015-03-01

The previous version of our cardiac thin filament (CTF) model consisted of the troponin complex (cTn), two coiled-coil dimers of tropomyosin (Tm), and 29 actin units. We now present the newest revision of the model to include explicit solvation. The model was developed to continue our study of genetic mutations in the CTF proteins which are linked to familial hypertrophic cardiomyopathies. Binding of calcium to the cTnC subunit causes subtle conformational changes to propagate through the cTnC to the cTnI subunit which then detaches from actin. Conformational changes propagate through to the cTnT subunit, which allows Tm to move into the open position along actin, leading to muscle contraction. Calcium disassociation allows for the reverse to occur, which results in muscle relaxation. The inclusion of explicit TIP3 water solvation allows for the model to get better individual local solvent to protein interactions; which are important when observing the N-lobe calcium binding pocket of the cTnC. We are able to compare in silica and in vitro experimental results to better understand the physiological effects from mutants, such as the R92L/W and F110V/I of the cTnT, on the calcium binding affinity compared to the wild type.

Explicit Not Implicit Preferences Predict Conservation Intentions for Endangered Species and Biomes.

PubMed

Echeverri, Alejandra; Callahan, Megan M; Chan, Kai M A; Satterfield, Terre; Zhao, Jiaying

2017-01-01

Conservation of biodiversity is determined in part by human preferences. Preferences relevant to conservation have been examined largely via explicit measures (e.g., a self-reported degree of liking), with implicit measures (e.g., preconscious, automatic evaluations) receiving relatively less attention. This is the case despite psychological evidence from other contexts that implicit preferences are more informative of behavior. Thus, the type of measure that predicts conservation intentions for biodiversity is unknown. We conducted three studies to examine conservation intentions in light of people's explicit and implicit preferences toward four endangered species (sea otter, American badger, caribou, yellow-breasted chat) and four biomes (forest, ocean, grassland, tundra). In Study 1 (n = 55), we found that people implicitly preferred caribou most, but explicitly preferred sea otter most, with a significant multiple regression where participants' explicit preferences dictated their stated intended donations for conservation of each species. In Study 2 (n = 57) we found that people implicitly and explicitly preferred forest and ocean over grassland and tundra. Explicit rather than implicit preferences predicted the intended donation for conservation of the ocean biome. Study 3 involved a broader online sample of participants (n = 463) and also found that explicit preferences dictated the intended donations for conservation of biomes and species. Our findings reveal discrepancies between implicit and explicit preferences toward species, but not toward biomes. Importantly, the results demonstrate that explicit rather than implicit preferences predict conservation intentions for biodiversity. The current findings have several implications for conservation and the communication of biodiversity initiatives.

Asking better questions: How presentation formats influence information search.

PubMed

Wu, Charley M; Meder, Björn; Filimon, Flavia; Nelson, Jonathan D

2017-08-01

While the influence of presentation formats have been widely studied in Bayesian reasoning tasks, we present the first systematic investigation of how presentation formats influence information search decisions. Four experiments were conducted across different probabilistic environments, where subjects (N = 2,858) chose between 2 possible search queries, each with binary probabilistic outcomes, with the goal of maximizing classification accuracy. We studied 14 different numerical and visual formats for presenting information about the search environment, constructed across 6 design features that have been prominently related to improvements in Bayesian reasoning accuracy (natural frequencies, posteriors, complement, spatial extent, countability, and part-to-whole information). The posterior variants of the icon array and bar graph formats led to the highest proportion of correct responses, and were substantially better than the standard probability format. Results suggest that presenting information in terms of posterior probabilities and visualizing natural frequencies using spatial extent (a perceptual feature) were especially helpful in guiding search decisions, although environments with a mixture of probabilistic and certain outcomes were challenging across all formats. Subjects who made more accurate probability judgments did not perform better on the search task, suggesting that simple decision heuristics may be used to make search decisions without explicitly applying Bayesian inference to compute probabilities. We propose a new take-the-difference (TTD) heuristic that identifies the accuracy-maximizing query without explicit computation of posterior probabilities. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Geminal-spanning orbitals make explicitly correlated reduced-scaling coupled-cluster methods robust, yet simple

NASA Astrophysics Data System (ADS)

Pavošević, Fabijan; Neese, Frank; Valeev, Edward F.

2014-08-01

We present a production implementation of reduced-scaling explicitly correlated (F12) coupled-cluster singles and doubles (CCSD) method based on pair-natural orbitals (PNOs). A key feature is the reformulation of the explicitly correlated terms using geminal-spanning orbitals that greatly reduce the truncation errors of the F12 contribution. For the standard S66 benchmark of weak intermolecular interactions, the cc-pVDZ-F12 PNO CCSD F12 interaction energies reproduce the complete basis set CCSD limit with mean absolute error <0.1 kcal/mol, and at a greatly reduced cost compared to the conventional CCSD F12.

Semantic processes leading to true and false memory formation in schizophrenia.

PubMed

Paz-Alonso, Pedro M; Ghetti, Simona; Ramsay, Ian; Solomon, Marjorie; Yoon, Jong; Carter, Cameron S; Ragland, J Daniel

2013-07-01

Encoding semantic relationships between items on word lists (semantic processing) enhances true memories, but also increases memory distortions. Episodic memory impairments in schizophrenia (SZ) are strongly driven by failures to process semantic relations, but the exact nature of these relational semantic processing deficits is not well understood. Here, we used a false memory paradigm to investigate the impact of implicit and explicit semantic processing manipulations on episodic memory in SZ. Thirty SZ and 30 demographically matched healthy controls (HC) studied Deese/Roediger-McDermott (DRM) lists of semantically associated words. Half of the lists had strong implicit semantic associations and the remainder had low strength associations. Similarly, half of the lists were presented under "standard" instructions and the other half under explicit "relational processing" instructions. After study, participants performed recall and old/new recognition tests composed of targets, critical lures, and unrelated lures. HC exhibited higher true memories and better discriminability between true and false memory compared to SZ. High, versus low, associative strength increased false memory rates in both groups. However, explicit "relational processing" instructions positively improved true memory rates only in HC. Finally, true and false memory rates were associated with severity of disorganized and negative symptoms in SZ. These results suggest that reduced processing of semantic relationships during encoding in SZ may stem from an inability to implement explicit relational processing strategies rather than a fundamental deficit in the implicit activation and retrieval of word meanings from patients' semantic lexicon. Copyright © 2013 Elsevier B.V. All rights reserved.

Effective Social Relationship Measurement and Cluster Based Routing in Mobile Opportunistic Networks †

PubMed Central

Zeng, Feng; Zhao, Nan; Li, Wenjia

2017-01-01

In mobile opportunistic networks, the social relationship among nodes has an important impact on data transmission efficiency. Motivated by the strong share ability of “circles of friends” in communication networks such as Facebook, Twitter, Wechat and so on, we take a real-life example to show that social relationships among nodes consist of explicit and implicit parts. The explicit part comes from direct contact among nodes, and the implicit part can be measured through the “circles of friends”. We present the definitions of explicit and implicit social relationships between two nodes, adaptive weights of explicit and implicit parts are given according to the contact feature of nodes, and the distributed mechanism is designed to construct the “circles of friends” of nodes, which is used for the calculation of the implicit part of social relationship between nodes. Based on effective measurement of social relationships, we propose a social-based clustering and routing scheme, in which each node selects the nodes with close social relationships to form a local cluster, and the self-control method is used to keep all cluster members always having close relationships with each other. A cluster-based message forwarding mechanism is designed for opportunistic routing, in which each node only forwards the copy of the message to nodes with the destination node as a member of the local cluster. Simulation results show that the proposed social-based clustering and routing outperforms the other classic routing algorithms. PMID:28498309

Effective Social Relationship Measurement and Cluster Based Routing in Mobile Opportunistic Networks.

PubMed

Zeng, Feng; Zhao, Nan; Li, Wenjia

2017-05-12

In mobile opportunistic networks, the social relationship among nodes has an important impact on data transmission efficiency. Motivated by the strong share ability of "circles of friends" in communication networks such as Facebook, Twitter, Wechat and so on, we take a real-life example to show that social relationships among nodes consist of explicit and implicit parts. The explicit part comes from direct contact among nodes, and the implicit part can be measured through the "circles of friends". We present the definitions of explicit and implicit social relationships between two nodes, adaptive weights of explicit and implicit parts are given according to the contact feature of nodes, and the distributed mechanism is designed to construct the "circles of friends" of nodes, which is used for the calculation of the implicit part of social relationship between nodes. Based on effective measurement of social relationships, we propose a social-based clustering and routing scheme, in which each node selects the nodes with close social relationships to form a local cluster, and the self-control method is used to keep all cluster members always having close relationships with each other. A cluster-based message forwarding mechanism is designed for opportunistic routing, in which each node only forwards the copy of the message to nodes with the destination node as a member of the local cluster. Simulation results show that the proposed social-based clustering and routing outperforms the other classic routing algorithms.

Translating visual information into action predictions: Statistical learning in action and nonaction contexts.

PubMed

Monroy, Claire D; Gerson, Sarah A; Hunnius, Sabine

2018-05-01

Humans are sensitive to the statistical regularities in action sequences carried out by others. In the present eyetracking study, we investigated whether this sensitivity can support the prediction of upcoming actions when observing unfamiliar action sequences. In two between-subjects conditions, we examined whether observers would be more sensitive to statistical regularities in sequences performed by a human agent versus self-propelled 'ghost' events. Secondly, we investigated whether regularities are learned better when they are associated with contingent effects. Both implicit and explicit measures of learning were compared between agent and ghost conditions. Implicit learning was measured via predictive eye movements to upcoming actions or events, and explicit learning was measured via both uninstructed reproduction of the action sequences and verbal reports of the regularities. The findings revealed that participants, regardless of condition, readily learned the regularities and made correct predictive eye movements to upcoming events during online observation. However, different patterns of explicit-learning outcomes emerged following observation: Participants were most likely to re-create the sequence regularities and to verbally report them when they had observed an actor create a contingent effect. These results suggest that the shift from implicit predictions to explicit knowledge of what has been learned is facilitated when observers perceive another agent's actions and when these actions cause effects. These findings are discussed with respect to the potential role of the motor system in modulating how statistical regularities are learned and used to modify behavior.

Synchronization of spontaneous eyeblinks while viewing video stories

PubMed Central

Nakano, Tamami; Yamamoto, Yoshiharu; Kitajo, Keiichi; Takahashi, Toshimitsu; Kitazawa, Shigeru

2009-01-01

Blinks are generally suppressed during a task that requires visual attention and tend to occur immediately before or after the task when the timing of its onset and offset are explicitly given. During the viewing of video stories, blinks are expected to occur at explicit breaks such as scene changes. However, given that the scene length is unpredictable, there should also be appropriate timing for blinking within a scene to prevent temporal loss of critical visual information. Here, we show that spontaneous blinks were highly synchronized between and within subjects when they viewed the same short video stories, but were not explicitly tied to the scene breaks. Synchronized blinks occurred during scenes that required less attention such as at the conclusion of an action, during the absence of the main character, during a long shot and during repeated presentations of a similar scene. In contrast, blink synchronization was not observed when subjects viewed a background video or when they listened to a story read aloud. The results suggest that humans share a mechanism for controlling the timing of blinks that searches for an implicit timing that is appropriate to minimize the chance of losing critical information while viewing a stream of visual events. PMID:19640888

Differential Age Effects for Implicit and Explicit Conceptual Associative Memory

PubMed Central

Dew, Ilana T. Z.; Giovanello, Kelly S.

2010-01-01

Older adults show disproportionate declines in explicit memory for associative relative to item information. However, the source of these declines is still uncertain. One explanation is a generalized impairment in the processing of associative information. A second explanation is a more specialized impairment in the strategic, effortful recollection of associative information, leaving less effortful forms of associative retrieval preserved. Assessing implicit memory of new associations is a way to distinguish between these viewpoints. To date, mixed findings have emerged from studies of associative priming in aging. One factor that may account for the variability is whether the manipulations inadvertently involve strategic, explicit processes. In 2 experiments we present a novel paradigm of conceptual associative priming in which subjects make speeded associative judgments about unrelated objects. Using a size classification task, Experiment 1 showed equivalent associative priming between young and older adults. Experiment 2 generalized the results of Experiment 1 to an inside/outside classification task, while replicating the typical age-related impairment in associative but not item recognition. Taken together, the findings support the viewpoint that older adults can incidentally encode and retrieve new meaningful associations despite difficulty with the intentional recollection of the same information. PMID:21077717

Contact-aware simulations of particulate Stokesian suspensions

NASA Astrophysics Data System (ADS)

Lu, Libin; Rahimian, Abtin; Zorin, Denis

2017-10-01

We present an efficient, accurate, and robust method for simulation of dense suspensions of deformable and rigid particles immersed in Stokesian fluid in two dimensions. We use a well-established boundary integral formulation for the problem as the foundation of our approach. This type of formulation, with a high-order spatial discretization and an implicit and adaptive time discretization, have been shown to be able to handle complex interactions between particles with high accuracy. Yet, for dense suspensions, very small time-steps or expensive implicit solves as well as a large number of discretization points are required to avoid non-physical contact and intersections between particles, leading to infinite forces and numerical instability. Our method maintains the accuracy of previous methods at a significantly lower cost for dense suspensions. The key idea is to ensure interference-free configuration by introducing explicit contact constraints into the system. While such constraints are unnecessary in the formulation, in the discrete form of the problem, they make it possible to eliminate catastrophic loss of accuracy by preventing contact explicitly. Introducing contact constraints results in a significant increase in stable time-step size for explicit time-stepping, and a reduction in the number of points adequate for stability.

Implicit LES using adaptive filtering

NASA Astrophysics Data System (ADS)

Sun, Guangrui; Domaradzki, Julian A.

2018-04-01

In implicit large eddy simulations (ILES) numerical dissipation prevents buildup of small scale energy in a manner similar to the explicit subgrid scale (SGS) models. If spectral methods are used the numerical dissipation is negligible but it can be introduced by applying a low-pass filter in the physical space, resulting in an effective ILES. In the present work we provide a comprehensive analysis of the numerical dissipation produced by different filtering operations in a turbulent channel flow simulated using a non-dissipative, pseudo-spectral Navier-Stokes solver. The amount of numerical dissipation imparted by filtering can be easily adjusted by changing how often a filter is applied. We show that when the additional numerical dissipation is close to the subgrid-scale (SGS) dissipation of an explicit LES the overall accuracy of ILES is also comparable, indicating that periodic filtering can replace explicit SGS models. A new method is proposed, which does not require any prior knowledge of a flow, to determine the filtering period adaptively. Once an optimal filtering period is found, the accuracy of ILES is significantly improved at low implementation complexity and computational cost. The method is general, performing well for different Reynolds numbers, grid resolutions, and filter shapes.

Lattice Boltzmann model for the compressible Navier-Stokes equations with flexible specific-heat ratio.

PubMed

Kataoka, Takeshi; Tsutahara, Michihisa

2004-03-01

We have developed a lattice Boltzmann model for the compressible Navier-Stokes equations with a flexible specific-heat ratio. Several numerical results are presented, and they agree well with the corresponding solutions of the Navier-Stokes equations. In addition, an explicit finite-difference scheme is proposed for the numerical calculation that can make a stable calculation with a large Courant number.

Implementing History and Philosophy in Science Teaching: Strategies, Methods, Results and Experiences from the European HIPST Project

ERIC Educational Resources Information Center

Hottecke, Dietmar; Henke, Andreas; Riess, Falk

2012-01-01

This paper presents a rationale for utilizing HPS to teach physics and the NoS developed in the course of a project funded by the European Union. A core feature of this approach is formed by the development of historical case studies for the use in lessons. Furthermore, the learners' perspectives are explicitly taken into account. Teaching methods…

Aerodynamic coefficients in generalized unsteady thin airfoil theory

NASA Technical Reports Server (NTRS)

Williams, M. H.

1980-01-01

Two cases are considered: (1) rigid body motion of an airfoil-flap combination consisting of vertical translation of given amplitude, rotation of given amplitude about a specified axis, and rotation of given amplitude of the control surface alone about its hinge; the upwash for this problem is defined mathematically; and (2) sinusoidal gust of given amplitude and wave number, for which the upwash is defined mathematically. Simple universal formulas are presented for the most important aerodynamic coefficients in unsteady thin airfoil theory. The lift and moment induced by a generalized gust are evaluated explicitly in terms of the gust wavelength. Similarly, in the control surface problem, the lift, moment, and hinge moments are given as explicit algebraic functions of hinge location. These results can be used together with any of the standard numerical inversion routines for the elementary loads (pitch and heave).

Discrepancies between implicit and explicit self-concepts of intelligence: relations to modesty, narcissism, and achievement motivation

PubMed Central

Gerstenberg, Friederike X. R.; Imhoff, Roland; Banse, Rainer; Schmitt, Manfred

2014-01-01

Previous research has shown that different configurations of the implicit self-concept of intelligence (iSCI) and the explicit self-concept of intelligence (eSCI) are consistently related to individuals’ performance on different intelligence tests (Dislich etal., 2012). The results indicated that any discrepant configuration between the iSCI and the eSCI impairs performance. In the present study, how correspondence between the iSCI and the eSCI is related to intelligence test performance as well as personality traits of modesty (low eSCI, high iSCI), narcissism (high eSCI, low iSCI), and achievement motivation was investigated. Furthermore, a moderated mediation analysis showed that the relation between the iSCI–eSCI configurations and intelligence test performance was mediated by achievement motivation for modest individuals. PMID:24575063

Strings in bubbling geometries and dual Wilson loop correlators

NASA Astrophysics Data System (ADS)

Aguilera-Damia, Jeremías; Correa, Diego H.; Fucito, Francesco; Giraldo-Rivera, Victor I.; Morales, Jose F.; Pando Zayas, Leopoldo A.

2017-12-01

We consider a fundamental string in a bubbling geometry of arbitrary genus dual to a half-supersymmetric Wilson loop in a general large representation R of the SU( N) gauge group in N=4 Supersymmetric Yang-Mills. We demonstrate, under some mild conditions, that the minimum value of the string classical action for a bubbling geometry of arbitrary genus precisely matches the correlator of a Wilson loop in the fundamental representation and one in a general large representation. We work out the case in which the large representation is given by a rectangular Young tableau, corresponding to a genus one bubbling geometry, explicitly. We also present explicit results in the field theory for a correlator of two Wilson loops: a large one in an arbitrary representation and a "small" one in the fundamental, totally symmetric or totally antisymmetric representation.

[Explicit memory for type font of words in source monitoring and recognition tasks].

PubMed

Hatanaka, Yoshiko; Fujita, Tetsuya

2004-02-01

We investigated whether people can consciously remember type fonts of words by methods of examining explicit memory; source-monitoring and old/new-recognition. We set matched, non-matched, and non-studied conditions between the study and the test words using two kinds of type fonts; Gothic and MARU. After studying words in one way of encoding, semantic or physical, subjects in a source-monitoring task made a three way discrimination between new words, Gothic words, and MARU words (Exp. 1). Subjects in an old/new-recognition task indicated whether test words were previously presented or not (Exp. 2). We compared the source judgments with old/new recognition data. As a result, these data showed conscious recollection for type font of words on the source monitoring task and dissociation between source monitoring and old/new recognition performance.

Social Organization, Population, and Land Use*

PubMed Central

Axinn, William G.; Ghimire, Dirgha J.

2011-01-01

We present a new approach to the investigation of human influences on environmental change that explicitly adds consideration of social organization. This approach identifies social organization as an influence on the environment that is independent of population size, affluence, and technology. The framework we present also identifies population events, such as births, that are likely to influence environmental outcomes beyond the consequences of population size. The theoretical framework we construct explains that explicit attention to social organization is necessary for micro-level investigation of the population-environment relationship because social organization influences both. We use newly available longitudinal, multilevel, mixed-method measures of local land use changes, local population dynamics, and social organization from the Nepalese Himalayas to provide empirical tests of this new framework. These tests reveal that measures of change in social organization are strongly associated with measures of change in land use, and that the association is independent of common measures of population size, affluence, and technology. Also, local birth events shape local land use changes and key proximate determinants of land use change. Together the empirical results demonstrate key new scientific opportunities arising from the approach we present. PMID:21876607

Explicit attention interferes with selective emotion processing in human extrastriate cortex.

PubMed

Schupp, Harald T; Stockburger, Jessica; Bublatzky, Florian; Junghöfer, Markus; Weike, Almut I; Hamm, Alfons O

2007-02-22

Brain imaging and event-related potential studies provide strong evidence that emotional stimuli guide selective attention in visual processing. A reflection of the emotional attention capture is the increased Early Posterior Negativity (EPN) for pleasant and unpleasant compared to neutral images (approximately 150-300 ms poststimulus). The present study explored whether this early emotion discrimination reflects an automatic phenomenon or is subject to interference by competing processing demands. Thus, emotional processing was assessed while participants performed a concurrent feature-based attention task varying in processing demands. Participants successfully performed the primary visual attention task as revealed by behavioral performance and selected event-related potential components (Selection Negativity and P3b). Replicating previous results, emotional modulation of the EPN was observed in a task condition with low processing demands. In contrast, pleasant and unpleasant pictures failed to elicit increased EPN amplitudes compared to neutral images in more difficult explicit attention task conditions. Further analyses determined that even the processing of pleasant and unpleasant pictures high in emotional arousal is subject to interference in experimental conditions with high task demand. Taken together, performing demanding feature-based counting tasks interfered with differential emotion processing indexed by the EPN. The present findings demonstrate that taxing processing resources by a competing primary visual attention task markedly attenuated the early discrimination of emotional from neutral picture contents. Thus, these results provide further empirical support for an interference account of the emotion-attention interaction under conditions of competition. Previous studies revealed the interference of selective emotion processing when attentional resources were directed to locations of explicitly task-relevant stimuli. The present data suggest that interference of emotion processing by competing task demands is a more general phenomenon extending to the domain of feature-based attention. Furthermore, the results are inconsistent with the notion of effortlessness, i.e., early emotion discrimination despite concurrent task demands. These findings implicate to assess the presumed automatic nature of emotion processing at the level of specific aspects rather than considering automaticity as an all-or-none phenomenon.

Event-related potential N270 as an index of social information conflict in explicit processing.

PubMed

Wang, Pei; Tan, Chen-Hao; Li, Yu; Zhang, Qin; Wang, Yi-Bo; Luo, Jun-Long

2018-01-01

As N270 has been widely shown to be sensitive to nonsocial information conflict, the present study investigated whether social information conflict can elicit increased N270 in either explicit or implicit processing conditions. Gender stereotype-related picture-word pairs and picture-word pairs in specific colors were used as social and nonsocial information, respectively. Participants performed an explicit task based on the S1-S2 paradigm in Study 1, and both social and nonsocial information conditions elicited larger N270 than the no-conflict condition. In Study 2, participants performed a word judgment task that was modified from the S1-S2 paradigm of Study 1. However, neither social information nor nonsocial information elicited larger N270 within the conflict condition. Social trials generally elicited a more negative ERP waveform than nonsocial trials overall. These findings suggest that N270 may reflect the processing of social information conflict only in explicit conditions and also that the cognitive basis of N270 is thus a general but explicit processing of working memory representation conflict. Copyright © 2017. Published by Elsevier B.V.

The role of feedback in implicit and explicit artificial grammar learning: a comparison between dyslexic and non-dyslexic adults.

PubMed

Schiff, Rachel; Sasson, Ayelet; Star, Galit; Kahta, Shani

2017-10-01

The importance of feedback for learning has been firmly established over the past few decades. The question of whether feedback plays a significant role in the statistical learning abilities of adults with dyslexia, however, is currently unresolved. Here, we examined the role of feedback in grammaticality judgment, type of structural knowledge, and confidence rating in both typically developed and dyslexic adults. We implemented two artificial grammar learning experiments: implicit and explicit. The second experiment was directly analogous to the first experiment in all respects except training format: the standard memorization instruction was replaced with an explicit rule-search instruction. Each experiment was conducted with and without performance feedback. While both groups showed significantly improved learning in the feedback-based explicit artificial grammar learning task, only the typically developed adults demonstrated higher levels of conscious structural knowledge. The present study demonstrates that the basis for the grammaticality judgment of adults with dyslexia differs from that of typically developed adults, regardless of increase in the level of explicitness.

Monitoring-induced disruption in skilled typewriting.

PubMed

Snyder, Kristy M; Logan, Gordon D

2013-10-01

It is often disruptive to attend to the details of one's expert performance. The current work presents four experiments that utilized a monitor to report protocol to evaluate the sufficiency of three accounts of monitoring-induced disruption. The inhibition hypothesis states that disruption results from costs associated with preparing to withhold inappropriate responses. The dual-task hypothesis states that disruption results from maintaining monitored information in working memory. The implicit-explicit hypothesis states that disruption results from explicitly monitoring details of performance that are normally implicit. The findings suggest that all three hypotheses are sufficient to produce disruption, but inhibition and dual-task costs are not necessary. Experiment 1 showed that monitoring to report was disruptive even when there was no requirement to inhibit. Experiment 2 showed that maintaining information in working memory caused some disruption but much less than monitoring to report. Experiment 4 showed that monitoring to inhibit was more disruptive than monitoring to report, suggesting that monitoring is more disruptive when it is combined with other task requirements, such as inhibition. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Selective attention affects implicit and explicit memory for familiar pictures at different delay conditions.

PubMed

Ballesteros, Soledad; Reales, José M; García, Eulalio; Carrasco, Marisa

2006-02-01

Three experiments investigated the effects of two variables -selective attention during encoding and delay between study and test- on implicit (picture fragment completion and object naming) and explicit (free recall and recognition) memory tests. Experiments 1 and 2 consistently indicated that (a) at all delays (immediate to 1 month), picture-fragment identification threshold was lower for the attended than the unattended pictures; (b) the attended pictures were recalled and recognized better than the unattended; and (c) attention and delay interacted in both memory tests. For implicit memory, performance decreased as delay increased for both attended and unattended pictures, but priming was more pronounced and lasted longer for the attended pictures; it was still present after a 1-month delay. For explicit memory, performance decreased as delay increased for attended pictures, but for unattended pictures performance was consistent throughout delay. By using a perceptual object naming task, Experiment 3 showed reliable implicit and explicit memory for attended but not for unattended pictures. This study indicates that picture repetition priming requires attention at the time of study and that neither delay nor attention dissociate performance in explicit and implicit memory tests; both types of memory require attention, but explicit memory does so to a larger degree.

Medial temporal lobe-dependent repetition suppression and enhancement due to implicit vs. explicit processing of individual repeated search displays

PubMed Central

Geyer, Thomas; Baumgartner, Florian; Müller, Hermann J.; Pollmann, Stefan

2012-01-01

Using visual search, functional magnetic resonance imaging (fMRI) and patient studies have demonstrated that medial temporal lobe (MTL) structures differentiate repeated from novel displays—even when observers are unaware of display repetitions. This suggests a role for MTL in both explicit and, importantly, implicit learning of repeated sensory information (Greene et al., 2007). However, recent behavioral studies suggest, by examining visual search and recognition performance concurrently, that observers have explicit knowledge of at least some of the repeated displays (Geyer et al., 2010). The aim of the present fMRI study was thus to contribute new evidence regarding the contribution of MTL structures to explicit vs. implicit learning in visual search. It was found that MTL activation was increased for explicit and, respectively, decreased for implicit relative to baseline displays. These activation differences were most pronounced in left anterior parahippocampal cortex (aPHC), especially when observers were highly trained on the repeated displays. The data are taken to suggest that explicit and implicit memory processes are linked within MTL structures, but expressed via functionally separable mechanisms (repetition-enhancement vs. -suppression). They further show that repetition effects in visual search would have to be investigated at the display level. PMID:23060776

Analytical Studies on the Synchronization of a Network of Linearly-Coupled Simple Chaotic Systems

NASA Astrophysics Data System (ADS)

Sivaganesh, G.; Arulgnanam, A.; Seethalakshmi, A. N.; Selvaraj, S.

2018-05-01

We present explicit generalized analytical solutions for a network of linearly-coupled simple chaotic systems. Analytical solutions are obtained for the normalized state equations of a network of linearly-coupled systems driven by a common chaotic drive system. Two parameter bifurcation diagrams revealing the various hidden synchronization regions, such as complete, phase and phase-lag synchronization are identified using the analytical results. The synchronization dynamics and their stability are studied using phase portraits and the master stability function, respectively. Further, experimental results for linearly-coupled simple chaotic systems are presented to confirm the analytical results. The synchronization dynamics of a network of chaotic systems studied analytically is reported for the first time.

Consider the source: persuasion of implicit evaluations is moderated by source credibility.

PubMed

Smith, Colin Tucker; De Houwer, Jan; Nosek, Brian A

2013-02-01

The long history of persuasion research shows how to change explicit, self-reported evaluations through direct appeals. At the same time, research on how to change implicit evaluations has focused almost entirely on techniques of retraining existing evaluations or manipulating contexts. In five studies, we examined whether direct appeals can change implicit evaluations in the same way as they do explicit evaluations. In five studies, both explicit and implicit evaluations showed greater evidence of persuasion following information presented by a highly credible source than a source low in credibility. Whereas cognitive load did not alter the effect of source credibility on explicit evaluations, source credibility had an effect on the persuasion of implicit evaluations only when participants were encouraged and able to consider information about the source. Our findings reveal the relevance of persuasion research for changing implicit evaluations and provide new ideas about the processes underlying both types of evaluation.

A Dual-Process Approach to the Role of Mother's Implicit and Explicit Attitudes toward Their Child in Parenting Models

ERIC Educational Resources Information Center

Sturge-Apple, Melissa L.; Rogge, Ronald D.; Skibo, Michael A.; Peltz, Jack S.; Suor, Jennifer H.

2015-01-01

Extending dual process frameworks of cognition to a novel domain, the present study examined how mothers' explicit and implicit attitudes about her child may operate in models of parenting. To assess implicit attitudes, two separate studies were conducted using the same child-focused Go/No-go Association Task (GNAT-Child). In Study 1, model…

The Differential Effects of Implicit and Explicit Feedback on Second Language (L2) Learners at Different Proficiency Levels

ERIC Educational Resources Information Center

Li, Shaofeng

2009-01-01

The present study investigates the differential effects of explicit and implicit feedback on L2 learners at different proficiency levels as measured by L2 development and learner uptake, which is defined as the learner's responses following feedback. Twenty-three learners of Chinese as a foreign language at two different levels of proficiency at a…

Aerosol-cloud interactions in a multi-scale modeling framework

NASA Astrophysics Data System (ADS)

Lin, G.; Ghan, S. J.

2017-12-01

Atmospheric aerosols play an important role in changing the Earth's climate through scattering/absorbing solar and terrestrial radiation and interacting with clouds. However, quantification of the aerosol effects remains one of the most uncertain aspects of current and future climate projection. Much of the uncertainty results from the multi-scale nature of aerosol-cloud interactions, which is very challenging to represent in traditional global climate models (GCMs). In contrast, the multi-scale modeling framework (MMF) provides a viable solution, which explicitly resolves the cloud/precipitation in the cloud resolved model (CRM) embedded in the GCM grid column. In the MMF version of community atmospheric model version 5 (CAM5), aerosol processes are treated with a parameterization, called the Explicit Clouds Parameterized Pollutants (ECPP). It uses the cloud/precipitation statistics derived from the CRM to treat the cloud processing of aerosols on the GCM grid. However, this treatment treats clouds on the CRM grid but aerosols on the GCM grid, which is inconsistent with the reality that cloud-aerosol interactions occur on the cloud scale. To overcome the limitation, here, we propose a new aerosol treatment in the MMF: Explicit Clouds Explicit Aerosols (ECEP), in which we resolve both clouds and aerosols explicitly on the CRM grid. We first applied the MMF with ECPP to the Accelerated Climate Modeling for Energy (ACME) model to have an MMF version of ACME. Further, we also developed an alternative version of ACME-MMF with ECEP. Based on these two models, we have conducted two simulations: one with the ECPP and the other with ECEP. Preliminary results showed that the ECEP simulations tend to predict higher aerosol concentrations than ECPP simulations, because of the more efficient vertical transport from the surface to the higher atmosphere but the less efficient wet removal. We also found that the cloud droplet number concentrations are also different between the two simulations due to the difference in the cloud droplet lifetime. Next, we will explore how the ECEP treatment affects the anthropogenic aerosol forcing, particularly the aerosol indirect forcing, by comparing present-day and pre-industrial simulations.

Implicit Attitudes towards People with Intellectual Disabilities: Their Relationship with Explicit Attitudes, Social Distance, Emotions and Contact

PubMed Central

Wilson, Michelle Clare; Scior, Katrina

2015-01-01

Implicit attitude research has expanded rapidly over the last decade and is seen as very promising as it counters biases present in much attitude research such as social desirability. However, most research in the area of intellectual disabilities has focused on explicit attitudes alone. This study examined implicit attitudes to this population and also examined their association with emotional reactions and contact, which have previously been found to have a significant influence on attitudes and stigma. A web based survey consisting of a single target Implicit Association Test, measures of explicit attitudes, social distance, and emotional reactions towards and contact with individuals with intellectual disabilities was completed by 326 adult UK residents. Implicit attitudes were not significantly associated with explicit attitudes, social distance or emotional reactions. Instead there were small to moderate associations between emotional reactions and explicit attitudes and social distance. Implicit attitudes did not vary according to participants’ level of contact with individuals with intellectual disabilities, type of the contact relationship (voluntary versus involuntary), gender or educational attainment. In contrast, these participant characteristics did affect explicit attitudes and social distance. Implicit attitudes towards individuals with intellectual disabilities were somewhat negative and, unlike explicit attitudes and stigma, did not vary according to participant demographics or contact. As they may have a negative impact on the lives of people with intellectual disabilities, implicit attitudes merit increased attention in research and interventions in the intellectual disabilities field. PMID:26366575

Implicit Attitudes towards People with Intellectual Disabilities: Their Relationship with Explicit Attitudes, Social Distance, Emotions and Contact.

PubMed

Wilson, Michelle Clare; Scior, Katrina

2015-01-01

Implicit attitude research has expanded rapidly over the last decade and is seen as very promising as it counters biases present in much attitude research such as social desirability. However, most research in the area of intellectual disabilities has focused on explicit attitudes alone. This study examined implicit attitudes to this population and also examined their association with emotional reactions and contact, which have previously been found to have a significant influence on attitudes and stigma. A web based survey consisting of a single target Implicit Association Test, measures of explicit attitudes, social distance, and emotional reactions towards and contact with individuals with intellectual disabilities was completed by 326 adult UK residents. Implicit attitudes were not significantly associated with explicit attitudes, social distance or emotional reactions. Instead there were small to moderate associations between emotional reactions and explicit attitudes and social distance. Implicit attitudes did not vary according to participants' level of contact with individuals with intellectual disabilities, type of the contact relationship (voluntary versus involuntary), gender or educational attainment. In contrast, these participant characteristics did affect explicit attitudes and social distance. Implicit attitudes towards individuals with intellectual disabilities were somewhat negative and, unlike explicit attitudes and stigma, did not vary according to participant demographics or contact. As they may have a negative impact on the lives of people with intellectual disabilities, implicit attitudes merit increased attention in research and interventions in the intellectual disabilities field.

Development of a grid-independent approximate Riemannsolver. Ph.D. Thesis - Michigan Univ.

NASA Technical Reports Server (NTRS)

Rumsey, Christopher Lockwood

1991-01-01

A grid-independent approximate Riemann solver for use with the Euler and Navier-Stokes equations was introduced and explored. The two-dimensional Euler and Navier-Stokes equations are described in Cartesian and generalized coordinates, as well as the traveling wave form of the Euler equations. The spatial and temporal discretization are described for both explicit and implicit time-marching schemes. The grid-aligned flux function of Roe is outlined, while the 5-wave grid-independent flux function is derived. The stability and monotonicity analysis of the 5-wave model are presented. Two-dimensional results are provided and extended to three dimensions. The corresponding results are presented.

Predictive Validity of Explicit and Implicit Threat Overestimation in Contamination Fear

PubMed Central

Green, Jennifer S.; Teachman, Bethany A.

2012-01-01

We examined the predictive validity of explicit and implicit measures of threat overestimation in relation to contamination-fear outcomes using structural equation modeling. Undergraduate students high in contamination fear (N = 56) completed explicit measures of contamination threat likelihood and severity, as well as looming vulnerability cognitions, in addition to an implicit measure of danger associations with potential contaminants. Participants also completed measures of contamination-fear symptoms, as well as subjective distress and avoidance during a behavioral avoidance task, and state looming vulnerability cognitions during an exposure task. The latent explicit (but not implicit) threat overestimation variable was a significant and unique predictor of contamination fear symptoms and self-reported affective and cognitive facets of contamination fear. On the contrary, the implicit (but not explicit) latent measure predicted behavioral avoidance (at the level of a trend). Results are discussed in terms of differential predictive validity of implicit versus explicit markers of threat processing and multiple fear response systems. PMID:24073390

On Spatially Explicit Models of Cholera Epidemics: Hydrologic controls, environmental drivers, human-mediated transmissions (Invited)

NASA Astrophysics Data System (ADS)

Rinaldo, A.; Bertuzzo, E.; Mari, L.; Righetto, L.; Gatto, M.; Casagrandi, R.; Rodriguez-Iturbe, I.

2010-12-01

A recently proposed model for cholera epidemics is examined. The model accounts for local communities of susceptibles and infectives in a spatially explicit arrangement of nodes linked by networks having different topologies. The vehicle of infection (Vibrio cholerae) is transported through the network links which are thought of as hydrological connections among susceptible communities. The mathematical tools used are borrowed from general schemes of reactive transport on river networks acting as the environmental matrix for the circulation and mixing of water-borne pathogens. The results of a large-scale application to the Kwa Zulu (Natal) epidemics of 2001-2002 will be discussed. Useful theoretical results derived in the spatially-explicit context will also be reviewed (like e.g. the exact derivation of the speed of propagation for traveling fronts of epidemics on regular lattices endowed with uniform population density). Network effects will be discussed. The analysis of the limit case of uniformly distributed population density proves instrumental in establishing the overall conditions for the relevance of spatially explicit models. To that extent, it is shown that the ratio between spreading and disease outbreak timescales proves the crucial parameter. The relevance of our results lies in the major differences potentially arising between the predictions of spatially explicit models and traditional compartmental models of the SIR-like type. Our results suggest that in many cases of real-life epidemiological interest timescales of disease dynamics may trigger outbreaks that significantly depart from the predictions of compartmental models. Finally, a view on further developments includes: hydrologically improved aquatic reservoir models for pathogens; human mobility patterns affecting disease propagation; double-peak emergence and seasonality in the spatially explicit epidemic context.

Do puzzle pieces and autism puzzle piece logos evoke negative associations?

PubMed

Gernsbacher, Morton Ann; Raimond, Adam R; Stevenson, Jennifer L; Boston, Jilana S; Harp, Bev

2018-02-01

Puzzle pieces have become ubiquitous symbols for autism. However, puzzle-piece imagery stirs debate between those who support and those who object to its use because they believe puzzle-piece imagery evokes negative associations. Our study empirically investigated whether puzzle pieces evoke negative associations in the general public. Participants' ( N = 400) implicit negative associations were measured with an Implicit Association Task, which is a speeded categorization task, and participants' explicit associations were measured with an Explicit Association Task, which is a standard task for assessing consumers' explicit associations with brands (and images of those brands). Puzzle pieces, both those used as autism logos and those used more generically, evoked negative implicit associations ( t(399) = -5.357, p < 0.001) and negative explicit associations ( z = 4.693, p < 0.001, d = 0.491). Participants explicitly associated puzzle pieces, even generic puzzle pieces, with incompleteness, imperfection, and oddity. Our results bear public policy implications. If an organization's intention for using puzzle-piece imagery is to evoke negative associations, our results suggest the organization's use of puzzle-piece imagery is apt. However, if the organization's intention is to evoke positive associations, our results suggest that puzzle-piece imagery should probably be avoided.

Asymmetrical booster ascent guidance and control system design study. Volume 5: Space shuttle powered explicit guidance. [space shuttle development

NASA Technical Reports Server (NTRS)

Jaggers, R. F.

1974-01-01

An optimum powered explicit guidance algorithm capable of handling all space shuttle exoatospheric maneuvers is presented. The theoretical and practical basis for the currently baselined space shuttle powered flight guidance equations and logic is documented. Detailed flow diagrams for implementing the steering computations for all shuttle phases, including powered return to launch site (RTLS) abort, are also presented. Derivation of the powered RTLS algorithm is provided, as well as detailed flow diagrams for implementing the option. The flow diagrams and equations are compatible with the current powered flight documentation.

Deformation of phospholipid vesicles in an optical stretcher.

PubMed

Delabre, Ulysse; Feld, Kasper; Crespo, Eleonore; Whyte, Graeme; Sykes, Cecile; Seifert, Udo; Guck, Jochen

2015-08-14

Phospholipid vesicles are common model systems for cell membranes. Important aspects of the membrane function relate to its mechanical properties. Here we have investigated the deformation behaviour of phospholipid vesicles in a dual-beam laser trap, also called an optical stretcher. This study explicitly makes use of the inherent heating present in such traps to investigate the dependence of vesicle deformation on temperature. By using lasers with different wavelengths, optically induced mechanical stresses and temperature increase can be tuned fairly independently with a single setup. The phase transition temperature of vesicles can be clearly identified by an increase in deformation. In the case of no heating effects, a minimal model for drop deformation in an optical stretcher and a more specific model for vesicle deformation that takes explicitly into account the angular dependence of the optical stress are presented to account for the experimental results. Elastic constants are extracted from the fitting procedures, which agree with literature data. This study demonstrates the utility of optical stretching, which is easily combined with microfluidic delivery, for the future serial, high-throughput study of the mechanical and thermodynamic properties of phospholipid vesicles.

Improved Satellite-based Crop Yield Mapping by Spatially Explicit Parameterization of Crop Phenology

NASA Astrophysics Data System (ADS)

Jin, Z.; Azzari, G.; Lobell, D. B.

2016-12-01

Field-scale mapping of crop yields with satellite data often relies on the use of crop simulation models. However, these approaches can be hampered by inaccuracies in the simulation of crop phenology. Here we present and test an approach to use dense time series of Landsat 7 and 8 acquisitions data to calibrate various parameters related to crop phenology simulation, such as leaf number and leaf appearance rates. These parameters are then mapped across the Midwestern United States for maize and soybean, and for two different simulation models. We then implement our recently developed Scalable satellite-based Crop Yield Mapper (SCYM) with simulations reflecting the improved phenology parameterizations, and compare to prior estimates based on default phenology routines. Our preliminary results show that the proposed method can effectively alleviate the underestimation of early-season LAI by the default Agricultural Production Systems sIMulator (APSIM), and that spatially explicit parameterization for the phenology model substantially improves the SCYM performance in capturing the spatiotemporal variation in maize and soybean yield. The scheme presented in our study thus preserves the scalability of SCYM, while significantly reducing its uncertainty.

Calibration of piezoelectric RL shunts with explicit residual mode correction

NASA Astrophysics Data System (ADS)

Høgsberg, Jan; Krenk, Steen

2017-01-01

Piezoelectric RL (resistive-inductive) shunts are passive resonant devices used for damping of dominant vibration modes of a flexible structure and their efficiency relies on the precise calibration of the shunt components. In the present paper improved calibration accuracy is attained by an extension of the local piezoelectric transducer displacement by two additional terms, representing the flexibility and inertia contributions from the residual vibration modes not directly addressed by the shunt damping. This results in an augmented dynamic model for the targeted resonant vibration mode, in which the residual contributions, represented by two correction factors, modify both the apparent transducer capacitance and the shunt circuit impedance. Explicit expressions for the correction of the shunt circuit inductance and resistance are presented in a form that is generally applicable to calibration formulae derived on the basis of an assumed single-mode structure, where modal interaction has been neglected. A design procedure is devised and subsequently verified by a numerical example, which demonstrates that effective mitigation can be obtained for an arbitrary vibration mode when the residual mode correction is included in the calibration of the RL shunt.

Midbond basis functions for weakly bound complexes

NASA Astrophysics Data System (ADS)

Shaw, Robert A.; Hill, J. Grant

2018-06-01

Weakly bound systems present a difficult problem for conventional atom-centred basis sets due to large separations, necessitating the use of large, computationally expensive bases. This can be remedied by placing a small number of functions in the region between molecules in the complex. We present compact sets of optimised midbond functions for a range of complexes involving noble gases, alkali metals and small molecules for use in high accuracy coupled -cluster calculations, along with a more robust procedure for their optimisation. It is shown that excellent results are possible with double-zeta quality orbital basis sets when a few midbond functions are added, improving both the interaction energy and the equilibrium bond lengths of a series of noble gas dimers by 47% and 8%, respectively. When used in conjunction with explicitly correlated methods, near complete basis set limit accuracy is readily achievable at a fraction of the cost that using a large basis would entail. General purpose auxiliary sets are developed to allow explicitly correlated midbond function studies to be carried out, making it feasible to perform very high accuracy calculations on weakly bound complexes.

On Feeling Torn About One’s Sexuality

PubMed Central

Windsor-Shellard, Ben

2014-01-01

Three studies offer novel evidence addressing the consequences of explicit–implicit sexual orientation (SO) ambivalence. In Study 1, self-identified straight females completed explicit and implicit measures of SO. The results revealed that participants with greater SO ambivalence took longer responding to explicit questions about their sexual preferences, an effect moderated by the direction of ambivalence. Study 2 replicated this effect using a different paradigm. Study 3 included self-identified straight and gay female and male participants; participants completed explicit and implicit measures of SO, plus measures of self-esteem and affect regarding their SO. Among straight participants, the response time results replicated the findings of Studies 1 and 2. Among gay participants, trends suggested that SO ambivalence influenced time spent deliberating on explicit questions relevant to sexuality, but in a different way. Furthermore, the amount and direction of SO ambivalence was related to self-esteem. PMID:24972940

Comparison of Damage Path Predictions for Composite Laminates by Explicit and Standard Finite Element Analysis Tools

NASA Technical Reports Server (NTRS)

Bogert, Philip B.; Satyanarayana, Arunkumar; Chunchu, Prasad B.

2006-01-01

Splitting, ultimate failure load and the damage path in center notched composite specimens subjected to in-plane tension loading are predicted using progressive failure analysis methodology. A 2-D Hashin-Rotem failure criterion is used in determining intra-laminar fiber and matrix failures. This progressive failure methodology has been implemented in the Abaqus/Explicit and Abaqus/Standard finite element codes through user written subroutines "VUMAT" and "USDFLD" respectively. A 2-D finite element model is used for predicting the intra-laminar damages. Analysis results obtained from the Abaqus/Explicit and Abaqus/Standard code show good agreement with experimental results. The importance of modeling delamination in progressive failure analysis methodology is recognized for future studies. The use of an explicit integration dynamics code for simple specimen geometry and static loading establishes a foundation for future analyses where complex loading and nonlinear dynamic interactions of damage and structure will necessitate it.

On the thermodynamics of the Swift-Hohenberg theory

NASA Astrophysics Data System (ADS)

Espath, L. F. R.; Sarmiento, A. F.; Dalcin, L.; Calo, V. M.

2017-11-01

We present the microbalance including the microforces, the first- and second-order microstresses for the Swift-Hohenberg equation concomitantly with their constitutive equations, which are consistent with the free-energy imbalance. We provide an explicit form for the microstress structure for a free-energy functional endowed with second-order spatial derivatives. Additionally, we generalize the Swift-Hohenberg theory via a proper constitutive process. Finally, we present one highly resolved three-dimensional numerical simulation to demonstrate the particular form of the resulting microstresses and their interactions in the evolution of the Swift-Hohenberg equation.

An Agent-Based Model for Studying Child Maltreatment and Child Maltreatment Prevention

NASA Astrophysics Data System (ADS)

Hu, Xiaolin; Puddy, Richard W.

This paper presents an agent-based model that simulates the dynamics of child maltreatment and child maltreatment prevention. The developed model follows the principles of complex systems science and explicitly models a community and its families with multi-level factors and interconnections across the social ecology. This makes it possible to experiment how different factors and prevention strategies can affect the rate of child maltreatment. We present the background of this work and give an overview of the agent-based model and show some simulation results.

Nonlinear vibration of an axially loaded beam carrying rigid bodies

NASA Astrophysics Data System (ADS)

Barry, O.

2016-12-01

This paper investigates the nonlinear vibration due to mid-plane stretching of an axially loaded simply supported beam carrying multiple rigid masses. Explicit expressions and closed form solutions of both linear and nonlinear analysis of the present vibration problem are presented for the first time. The validity of the analytical model is demonstrated using finite element analysis and via comparison with the result in the literature. Parametric studies are conducted to examine how the nonlinear frequency and frequency response curve are affected by tension, rotational inertia, and number of intermediate rigid bodies.

Intact and impaired conceptual memory processes in amnesia.

PubMed

Keane, M M; Gabrieli, J D; Monti, L A; Fleischman, D A; Cantor, J M; Noland, J S

1997-01-01

To examine the status of conceptual memory processes in amnesia, a conceptual memory task with implicit or explicit task instructions was given to amnesic and control groups. After studying a list of category exemplars, participants saw category labels and were asked to generate as many exemplars as possible (an implicit memory task) or to generate exemplars that had been in the prior study list (an explicit memory task). After incidental deep or shallow encoding of exemplars, amnesic patients showed normal implicit memory performance (priming), a normal levels-of-processing effect on priming, and impaired explicit memory performance. After intentional encoding of exemplars, amnesic patients showed impaired implicit and explicit memory performance. Results suggest that although amnesic patients can show impairments on implicit and explicit conceptual memory tasks, their deficit does not generalize to all conceptual memory tasks.

Exploring implicit and explicit aspects of sense of agency

PubMed Central

Moore, J.W.; Middleton, D.; Haggard, P.; Fletcher, P.C.

2012-01-01

Sense of agency refers to the sense of initiating and controlling actions in order to influence events in the outside world. Recently, a distinction between implicit and explicit aspects of sense of agency has been proposed, analogous to distinctions found in other areas of cognition, notably learning. However, there is yet no strong evidence supporting separable implicit and explicit components of sense of agency. The so-called ‘Perruchet paradigm’ offers one of the few convincing demonstrations of separable implicit and explicit learning systems. We adopted this approach to evaluate the implicit–explicit distinction in the context of a simple task in which outcomes were probabilistically caused by actions. In line with our initial predictions, we found evidence of a dissociation. We discuss the implications of this result for theories of sense of agency. PMID:23143153

Explicit reference governor for linear systems

NASA Astrophysics Data System (ADS)

Garone, Emanuele; Nicotra, Marco; Ntogramatzidis, Lorenzo

2018-06-01

The explicit reference governor is a constrained control scheme that was originally introduced for generic nonlinear systems. This paper presents two explicit reference governor strategies that are specifically tailored for the constrained control of linear time-invariant systems subject to linear constraints. Both strategies are based on the idea of maintaining the system states within an invariant set which is entirely contained in the constraints. This invariant set can be constructed by exploiting either the Lyapunov inequality or modal decomposition. To improve the performance, we show that the two strategies can be combined by choosing at each time instant the least restrictive set. Numerical simulations illustrate that the proposed scheme achieves performances that are comparable to optimisation-based reference governors.

Learning STEM Through Integrative Visual Representations

NASA Astrophysics Data System (ADS)

Virk, Satyugjit Singh

Previous cognitive models of memory have not comprehensively taken into account the internal cognitive load of chunking isolated information and have emphasized the external cognitive load of visual presentation only. Under the Virk Long Term Working Memory Multimedia Model of cognitive load, drawing from the Cowan model, students presented with integrated animations of the key neural signal transmission subcomponents where the interrelationships between subcomponents are visually and verbally explicit, were hypothesized to perform significantly better on free response and diagram labeling questions, than students presented with isolated animations of these subcomponents. This is because the internal attentional cognitive load of chunking these concepts is greatly reduced and hence the overall cognitive load is less for the integrated visuals group than the isolated group, despite the higher external load for the integrated group of having the interrelationships between subcomponents presented explicitly. Experiment 1 demonstrated that integrating the subcomponents of the neuron significantly enhanced comprehension of the interconnections between cellular subcomponents and approached significance for enhancing comprehension of the layered molecular correlates of the cellular structures and their interconnections. Experiment 2 corrected time on task confounds from Experiment 1 and focused on the cellular subcomponents of the neuron only. Results from the free response essay subcomponent subscores did demonstrate significant differences in favor of the integrated group as well as some evidence from the diagram labeling section. Results from free response, short answer and What-If (problem solving), and diagram labeling detailed interrelationship subscores demonstrated the integrated group did indeed learn the extra material they were presented with. This data demonstrating the integrated group learned the extra material they were presented with provides some initial support for the assertion that chunking mediated the greater gains in learning for the neural subcomponent concepts over the control.

Functional differences between statistical learning with and without explicit training

PubMed Central

Reber, Paul J.; Paller, Ken A.

2015-01-01

Humans are capable of rapidly extracting regularities from environmental input, a process known as statistical learning. This type of learning typically occurs automatically, through passive exposure to environmental input. The presumed function of statistical learning is to optimize processing, allowing the brain to more accurately predict and prepare for incoming input. In this study, we ask whether the function of statistical learning may be enhanced through supplementary explicit training, in which underlying regularities are explicitly taught rather than simply abstracted through exposure. Learners were randomly assigned either to an explicit group or an implicit group. All learners were exposed to a continuous stream of repeating nonsense words. Prior to this implicit training, learners in the explicit group received supplementary explicit training on the nonsense words. Statistical learning was assessed through a speeded reaction-time (RT) task, which measured the extent to which learners used acquired statistical knowledge to optimize online processing. Both RTs and brain potentials revealed significant differences in online processing as a function of training condition. RTs showed a crossover interaction; responses in the explicit group were faster to predictable targets and marginally slower to less predictable targets relative to responses in the implicit group. P300 potentials to predictable targets were larger in the explicit group than in the implicit group, suggesting greater recruitment of controlled, effortful processes. Taken together, these results suggest that information abstracted through passive exposure during statistical learning may be processed more automatically and with less effort than information that is acquired explicitly. PMID:26472644

Funnel Libraries for Real-Time Robust Feedback Motion Planning

DTIC Science & Technology

2016-07-21

motion plans for a robot that are guaranteed to suc- ceed despite uncertainty in the environment, parametric model uncertainty, and disturbances...resulting funnel library is then used to sequentially compose motion plans at runtime while ensuring the safety of the robot . A major advantage of...the work presented here is that by explicitly taking into account the effect of uncertainty, the robot can evaluate motion plans based on how vulnerable

Threshold law for electron-atom impact ionization

NASA Technical Reports Server (NTRS)

Temkin, A.

1982-01-01

A derivation of the explicit form of the threshold law for electron impact ionization of atoms is presented, based on the Coulomb-dipole theory. The important generalization is made of using a dipole function whose moment is the dipole moment formed by an inner electron and the nucleus. The result is a modulated quasi-linear law for the yield of positive ions which applies to positron-atom impact ionization.

Integrability and correspondence of classical and quantum non-linear three-mode systems

NASA Astrophysics Data System (ADS)

Odzijewicz, A.; Wawreniuk, E.

2018-04-01

The relationship between classical and quantum three one-mode systems interacting in a non-linear way is described. We investigate the integrability of these systems by using the reduction procedure. The reduced coherent states for the quantum system are constructed. We find the explicit formulas for the reproducing measure for these states. Examples of some applications of the obtained results in non-linear quantum optics are presented.

Finite Element Modeling of Coupled Flexible Multibody Dynamics and Liquid Sloshing

DTIC Science & Technology

2006-09-01

tanks is presented. The semi-discrete combined solid and fluid equations of motions are integrated using a time- accurate parallel explicit solver...Incompressible fluid flow in a moving/deforming container including accurate modeling of the free-surface, turbulence, and viscous effects ...paper, a single computational code which uses a time- accurate explicit solution procedure is used to solve both the solid and fluid equations of

Combined EDL-Mobility Planning for Planetary Missions

NASA Technical Reports Server (NTRS)

Kuwata, Yoshiaki; Balaram, Bob

2011-01-01

This paper presents an analysis framework for planetary missions that have coupled mobility and EDL (Entry-Descent-Landing) systems. Traditional systems engineering approaches to mobility missions such as MERs (Mars Exploration Rovers) and MSL (Mars Science Laboratory) independently study the EDL system and the mobility system, and does not perform explicit trade-off between them or risk minimization of the overall system. A major challenge is that EDL operation is inherently uncertain and its analysis results such as landing footprint are described using PDF (Probability Density Function). The proposed approach first builds a mobility cost-to-go map that encodes the driving cost of any point on the map to a science target location. The cost could include variety of metrics such as traverse distance, time, wheel rotation on soft soil, and closeness to hazards. It then convolves the mobility cost-to-go map with the landing PDF given by the EDL system, which provides a histogram of driving cost, which can be used to evaluate the overall risk of the mission. By capturing the coupling between EDL and mobility explicitly, this analysis framework enables quantitative tradeoff between EDL and mobility system performance, as well as the characterization of risks in a statistical way. The simulation results are presented with a realistic Mars terrain data

Incidental encoding of emotional pictures: affective bias studied through event related brain potentials.

PubMed

Tapia, Manuel; Carretié, Luis; Sierra, Benjamín; Mercado, Francisco

2008-06-01

Emotional stimuli are better remembered than neutral stimuli. Most of the studies taking into account this emotional bias refer to explicit memory, use behavioral measures of the recall and predict better recall of negative stimuli. The few studies taking into account implicit memory and the valence emotional dimension are inconclusive on the effect of the stimulus' emotional valence. In the present study, 120 pictures (30 positive, 30 negative, 30 relaxing and 30 neutral) were shown to, and assessed by, 28 participants (study phase). Subsequently, event related brain potentials (ERPs) were recorded during the presentation of 120 new (shown for the first time) and 120 old (already shown in the study phase) pictures (test phase). No explicit instructions or clues related to recovery were given to participants, and a distractor task was employed, in order to maintain implicit the memory assessment. As expected from other studies' data, our results showed that old stimuli elicited an enhanced late positive component 450 ms after stimulus onset (repetition effect). Moreover, this effect was modulated by the stimuli's emotional valence, since the most positively valenced stimuli were associated with a decreased repetition effect with respect to the most negatively valenced stimuli. This effect was located at ventromedial prefrontal cortex. These results suggest the existence of a valence-mediated bias in implicit memory.

Gluons and gravitons at one loop from ambitwistor strings

NASA Astrophysics Data System (ADS)

Geyer, Yvonne; Monteiro, Ricardo

2018-03-01

We present new and explicit formulae for the one-loop integrands of scattering amplitudes in non-supersymmetric gauge theory and gravity, valid for any number of particles. The results exhibit the colour-kinematics duality in gauge theory and the double-copy relation to gravity, in a form that was recently observed in supersymmetric theories. The new formulae are expressed in a particular representation of the loop integrand, with only one quadratic propagator, which arises naturally from the framework of the loop-level scattering equations. The starting point in our work are the expressions based on the scattering equations that were recently derived from ambitwistor string theory. We turn these expressions into explicit formulae depending only on the loop momentum, the external momenta and the external polarisations. These formulae are valid in any number of spacetime dimensions for pure Yang-Mills theory (gluon) and its natural double copy, NS-NS gravity (graviton, dilaton, B-field), and we also present formulae in four spacetime dimensions for pure gravity (graviton). We perform several tests of our results, such as checking gauge invariance and directly matching our four-particle formulae to previously known expressions. While these tests would be elaborate in a Feynman-type representation of the loop integrand, they become straightforward in the representation we use.

The large sample size fallacy.

PubMed

Lantz, Björn

2013-06-01

Significance in the statistical sense has little to do with significance in the common practical sense. Statistical significance is a necessary but not a sufficient condition for practical significance. Hence, results that are extremely statistically significant may be highly nonsignificant in practice. The degree of practical significance is generally determined by the size of the observed effect, not the p-value. The results of studies based on large samples are often characterized by extreme statistical significance despite small or even trivial effect sizes. Interpreting such results as significant in practice without further analysis is referred to as the large sample size fallacy in this article. The aim of this article is to explore the relevance of the large sample size fallacy in contemporary nursing research. Relatively few nursing articles display explicit measures of observed effect sizes or include a qualitative discussion of observed effect sizes. Statistical significance is often treated as an end in itself. Effect sizes should generally be calculated and presented along with p-values for statistically significant results, and observed effect sizes should be discussed qualitatively through direct and explicit comparisons with the effects in related literature. © 2012 Nordic College of Caring Science.

The Effects of Training Contingency Awareness During Attention Bias Modification on Learning and Stress Reactivity.

PubMed

Lazarov, Amit; Abend, Rany; Seidner, Shiran; Pine, Daniel S; Bar-Haim, Yair

2017-09-01

Current attention bias modification (ABM) procedures are designed to implicitly train attention away from threatening stimuli with the hope of reducing stress reactivity and anxiety symptoms. However, the mechanisms underlying effective ABM delivery are not well understood, with awareness of the training contingency suggested as one possible factor contributing to ABM efficacy. Here, 45 high-anxious participants were trained to divert attention away from threat in two ABM sessions. They were randomly assigned to one of three training protocols: an implicit protocol, comprising two standard implicit ABM training sessions; an explicit protocol, comprising two sessions with explicit instruction as to the attention training contingency; and an implicit-explicit protocol, in which participants were not informed of the training contingency in the first ABM session and informed of it at the start of the second session. We examined learning processes and stress reactivity following a stress-induction task. Results indicate that relative to implicit instructions, explicit instructions led to stronger learning during the first training session. Following rest, the explicit and implicit groups exhibited consolidation-related improvement in performance, whereas no such improvement was noted for the implicit-explicit group. Finally, although stress reactivity was reduced after training, contingency awareness did not yield a differential effect on stress reactivity measured using both self-reports and skin conductance, within and across sessions. These results suggest that explicit ABM administration leads to greater initial learning during the training protocol while not differing from standard implicit administration in terms of off-line learning and stress reactivity. Copyright © 2017. Published by Elsevier Ltd.

Evaluative Conditioning with Facial Stimuli in Dementia Patients.

PubMed

Blessing, Andreas; Zöllig, Jacqueline; Weierstall, Roland; Dammann, Gerhard; Martin, Mike

2013-01-01

We present results of a study investigating evaluative learning in dementia patients with a classic evaluative conditioning paradigm. Picture pairs of three unfamiliar faces with liked, disliked, or neutral faces, that were rated prior to the presentation, were presented 10 times each to a group of dementia patients (N = 15) and healthy controls (N = 14) in random order. Valence ratings of all faces were assessed before and after presentation. In contrast to controls, dementia patients changed their valence ratings of unfamiliar faces according to their pairing with either a liked or disliked face, although they were not able to explicitly assign the picture pairs after the presentation. Our finding suggests preserved evaluative conditioning in dementia patients. However, the result has to be considered preliminary, as it is unclear which factors prevented the predicted rating changes in the expected direction in the control group.

Some new results on the central overlap problem in astrometry

NASA Astrophysics Data System (ADS)

Rapaport, M.

1998-07-01

The central overlap problem in astrometry has been revisited in the recent last years by Eichhorn (1988) who explicitly inverted the matrix of a constrained least squares problem. In this paper, the general explicit solution of the unconstrained central overlap problem is given. We also give the explicit solution for an other set of constraints; this result is a confirmation of a conjecture expressed by Eichhorn (1988). We also consider the use of iterative methods to solve the central overlap problem. A surprising result is obtained when the classical Gauss Seidel method is used; the iterations converge immediately to the general solution of the equations; we explain this property writing the central overlap problem in a new set of variables.

Advances in the treatment of explicit water molecules in docking and binding free energy calculations.

PubMed

Hu, Xiao; Maffucci, Irene; Contini, Alessandro

2018-05-13

The inclusion of direct effects mediated by water during the ligand-receptor recognition is a hot-topic of modern computational chemistry applied to drug discovery and development. Docking or virtual screening with explicit hydration is still debatable, despite the successful cases that have been presented in the last years. Indeed, how to select the water molecules that will be included in the docking process or how the included waters should be treated remain open questions. In this review, we will discuss some of the most recent methods that can be used in computational drug discovery and drug development when the effect of a single water, or of a small network of interacting waters, needs to be explicitly considered. Here, we analyse software to aid the selection, or to predict the position, of water molecules that are going to be explicitly considered in later docking studies. We also present software and protocols able to efficiently treat flexible water molecules during docking, including examples of applications. Finally, we discuss methods based on molecular dynamics simulations that can be used to integrate docking studies or to reliably and efficiently compute binding energies of ligands in presence of interfacial or bridging water molecules. Software applications aiding the design of new drugs that exploit water molecules, either as displaceable residues or as bridges to the receptor, are constantly being developed. Although further validation is needed, workflows that explicitly consider water will probably become a standard for computational drug discovery soon. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Discrepancy between implicit and explicit preferences for food portions in obesity.

PubMed

Cserjesi, R; De Vos, I; Deroost, N

2016-09-01

We investigated the implicit preference in terms of food portion in obesity using the affective priming paradigm. Primes representing different portions of fast food (small, medium and large) were used to assess participants' readiness to respond to a positive or negative target word. A self-reported affective rating scale of food portion and a portion judgment task were administered to determine the explicit preference for food portion and portion misperception, respectively. The results of the affective priming paradigm showed an implicit preference for large food portions in the obese group. No implicit preference in terms of food portion was found in the non-obese group. The explicit preference measure of food portion demonstrated a rather negative attitude for large portions in the obese group, whereas the non-obese group reported no explicit preference in terms of food portion. Thus, unlike the non-obese group, the obese group showed clear discrepancies between implicit and explicit preferences in terms of food portion: obese participants demonstrated an implicit, but not an explicit preference for large food portions. These results could not be attributed to a misperception of food portion, as revealed by the portion judgment task. The current findings suggest that social desirability might conceal self-reported preference in terms of food portion and/or that obese individuals are less aware of their internal preferences.

Strings in bubbling geometries and dual Wilson loop correlators

DOE PAGES

Aguilera-Damia, Jeremias; Correa, Diego H.; Fucito, Francesco; ...

2017-12-20

We consider a fundamental string in a bubbling geometry of arbitrary genus dual to a half-supersymmetric Wilson loop in a general large representation R of the SU(N) gauge group in N = 4 Supersymmetric Yang-Mills. We demonstrate, under some mild conditions, that the minimum value of the string classical action for a bubbling geometry of arbitrary genus precisely matches the correlator of a Wilson loop in the fundamental representation and one in a general large representation. We work out the case in which the large representation is given by a rectangular Young tableau, corresponding to a genus one bubbling geometry,more » explicitly. Lastly, we also present explicit results in the field theory for a correlator of two Wilson loops: a large one in an arbitrary representation and a “small” one in the fundamental, totally symmetric or totally antisymmetric representation.« less

Incidental acquisition of foreign language vocabulary through brief multi-modal exposure.

PubMed

Bisson, Marie-Josée; van Heuven, Walter J B; Conklin, Kathy; Tunney, Richard J

2013-01-01

First language acquisition requires relatively little effort compared to foreign language acquisition and happens more naturally through informal learning. Informal exposure can also benefit foreign language learning, although evidence for this has been limited to speech perception and production. An important question is whether informal exposure to spoken foreign language also leads to vocabulary learning through the creation of form-meaning links. Here we tested the impact of exposure to foreign language words presented with pictures in an incidental learning phase on subsequent explicit foreign language learning. In the explicit learning phase, we asked adults to learn translation equivalents of foreign language words, some of which had appeared in the incidental learning phase. Results revealed rapid learning of the foreign language words in the incidental learning phase showing that informal exposure to multi-modal foreign language leads to foreign language vocabulary acquisition. The creation of form-meaning links during the incidental learning phase is discussed.

Altered responses to social chemosignals in autism spectrum disorder.

PubMed

Endevelt-Shapira, Yaara; Perl, Ofer; Ravia, Aharon; Amir, Daniel; Eisen, Ami; Bezalel, Vered; Rozenkrantz, Liron; Mishor, Eva; Pinchover, Liron; Soroka, Timna; Honigstein, Danielle; Sobel, Noam

2018-01-01

Autism spectrum disorder (ASD) is characterized by impaired social communication, often attributed to misreading of emotional cues. Why individuals with ASD misread emotions remains unclear. Given that terrestrial mammals rely on their sense of smell to read conspecific emotions, we hypothesized that misreading of emotional cues in ASD partially reflects altered social chemosignaling. We found no difference between typically developed (TD) and cognitively able adults with ASD at explicit detection and perception of social chemosignals. Nevertheless, TD and ASD participants dissociated in their responses to subliminal presentation of these same compounds: the undetected 'smell of fear' (skydiver sweat) increased physiological arousal and reduced explicit and implicit measures of trust in TD but acted opposite in ASD participants. Moreover, two different undetected synthetic putative social chemosignals increased or decreased arousal in TD but acted opposite in ASD participants. These results implicate social chemosignaling as a sensory substrate of social impairment in ASD.

Fluctuations of Wigner-type random matrices associated with symmetric spaces of class DIII and CI

NASA Astrophysics Data System (ADS)

Stolz, Michael

2018-02-01

Wigner-type randomizations of the tangent spaces of classical symmetric spaces can be thought of as ordinary Wigner matrices on which additional symmetries have been imposed. In particular, they fall within the scope of a framework, due to Schenker and Schulz-Baldes, for the study of fluctuations of Wigner matrices with additional dependencies among their entries. In this contribution, we complement the results of these authors by explicit calculations of the asymptotic covariances for symmetry classes DIII and CI and thus obtain explicit CLTs for these classes. On the technical level, the present work is an exercise in controlling the cumulative effect of systematically occurring sign factors in an involved sum of products by setting up a suitable combinatorial model for the summands. This aspect may be of independent interest. Research supported by Deutsche Forschungsgemeinschaft (DFG) via SFB 878.

A superstring field theory for supergravity

NASA Astrophysics Data System (ADS)

Reid-Edwards, R. A.; Riccombeni, D. A.

2017-09-01

A covariant closed superstring field theory, equivalent to classical tendimensional Type II supergravity, is presented. The defining conformal field theory is the ambitwistor string worldsheet theory of Mason and Skinner. This theory is known to reproduce the scattering amplitudes of Cachazo, He and Yuan in which the scattering equations play an important role and the string field theory naturally incorporates these results. We investigate the operator formalism description of the ambitwsitor string and propose an action for the string field theory of the bosonic and supersymmetric theories. The correct linearised gauge symmetries and spacetime actions are explicitly reproduced and evidence is given that the action is correct to all orders. The focus is on the NeveuSchwarz sector and the explicit description of tree level perturbation theory about flat spacetime. Application of the string field theory to general supergravity backgrounds and the inclusion of the Ramond sector are briefly discussed.

Strings in bubbling geometries and dual Wilson loop correlators

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

Aguilera-Damia, Jeremias; Correa, Diego H.; Fucito, Francesco

We consider a fundamental string in a bubbling geometry of arbitrary genus dual to a half-supersymmetric Wilson loop in a general large representation R of the SU(N) gauge group in N = 4 Supersymmetric Yang-Mills. We demonstrate, under some mild conditions, that the minimum value of the string classical action for a bubbling geometry of arbitrary genus precisely matches the correlator of a Wilson loop in the fundamental representation and one in a general large representation. We work out the case in which the large representation is given by a rectangular Young tableau, corresponding to a genus one bubbling geometry,more » explicitly. Lastly, we also present explicit results in the field theory for a correlator of two Wilson loops: a large one in an arbitrary representation and a “small” one in the fundamental, totally symmetric or totally antisymmetric representation.« less

Psychophysiological arousal and inter‐ and intraindividual differences in risk‐sensitive decision making

PubMed Central

Scheibehenne, Benjamin; Clark, Luke

2016-01-01

Abstract The current study assessed peripheral responses during decision making under explicit risk, and tested whether intraindividual variability in choice behavior can be explained by fluctuations in peripheral arousal. Electrodermal activity (EDA) and heart rate (HR) were monitored in healthy volunteers (N = 68) during the Roulette Betting Task. In this task, participants were presented with risky gambles to bet on, with the chances of winning varying across trials. Hierarchical Bayesian analyses demonstrated that EDA and HR acceleration responses during the decision phase were sensitive to the chances of winning. Interindividual differences in this peripheral reactivity during risky decision making were related to trait sensitivity to punishment and trait sensitivity to reward. Moreover, trial‐by‐trial variation in EDA and HR acceleration responses predicted a small portion of intraindividual variability in betting choices. Our results show that psychophysiological responses are sensitive to explicit risk and can help explain intraindividual heterogeneity in choice behavior. PMID:26927730

Attractive Serial Dependence in the Absence of an Explicit Task.

PubMed

Fornaciai, Michele; Park, Joonkoo

2018-03-01

Attractive serial dependence refers to an adaptive change in the representation of sensory information, whereby a current stimulus appears to be similar to a previous one. The nature of this phenomenon is controversial, however, as serial dependence could arise from biased perceptual representations or from biased traces of working memory representation at a decisional stage. Here, we demonstrated a neural signature of serial dependence in numerosity perception emerging early in the visual processing stream even in the absence of an explicit task. Furthermore, a psychophysical experiment revealed that numerosity perception is biased by a previously presented stimulus in an attractive way, not by repulsive adaptation. These results suggest that serial dependence is a perceptual phenomenon starting from early levels of visual processing and occurring independently from a decision process, which is consistent with the view that these biases smooth out noise from neural signals to establish perceptual continuity.

Identification of internal properties of fibres and micro-swimmers

NASA Astrophysics Data System (ADS)

Plouraboué, Franck; Thiam, E. Ibrahima; Delmotte, Blaise; Climent, Eric

2017-01-01

In this paper, we address the identifiability of constitutive parameters of passive or active micro-swimmers. We first present a general framework for describing fibres or micro-swimmers using a bead-model description. Using a kinematic constraint formulation to describe fibres, flagellum or cilia, we find explicit linear relationship between elastic constitutive parameters and generalized velocities from computing contact forces. This linear formulation then permits one to address explicitly identifiability conditions and solve for parameter identification. We show that both active forcing and passive parameters are both identifiable independently but not simultaneously. We also provide unbiased estimators for generalized elastic parameters in the presence of Langevin-like forcing with Gaussian noise using a Bayesian approach. These theoretical results are illustrated in various configurations showing the efficiency of the proposed approach for direct parameter identification. The convergence of the proposed estimators is successfully tested numerically.

Prediction of High-Lift Flows using Turbulent Closure Models

NASA Technical Reports Server (NTRS)

Rumsey, Christopher L.; Gatski, Thomas B.; Ying, Susan X.; Bertelrud, Arild

1997-01-01

The flow over two different multi-element airfoil configurations is computed using linear eddy viscosity turbulence models and a nonlinear explicit algebraic stress model. A subset of recently-measured transition locations using hot film on a McDonnell Douglas configuration is presented, and the effect of transition location on the computed solutions is explored. Deficiencies in wake profile computations are found to be attributable in large part to poor boundary layer prediction on the generating element, and not necessarily inadequate turbulence modeling in the wake. Using measured transition locations for the main element improves the prediction of its boundary layer thickness, skin friction, and wake profile shape. However, using measured transition locations on the slat still yields poor slat wake predictions. The computation of the slat flow field represents a key roadblock to successful predictions of multi-element flows. In general, the nonlinear explicit algebraic stress turbulence model gives very similar results to the linear eddy viscosity models.

Neural correlates of subliminally presented visual sexual stimuli.

PubMed

Wernicke, Martina; Hofter, Corinna; Jordan, Kirsten; Fromberger, Peter; Dechent, Peter; Müller, Jürgen L

2017-03-01

In the context of forensic psychiatry, it is crucial that diagnoses of deviant sexual interests are resistant to manipulation. In a first attempt to promote the development of such tools, the current fMRI study focusses on the examination of hemodynamic responses to preferred, in contrast to non-preferred, sexual stimuli with and without explicit sexual features in 24 healthy heterosexual subjects. The subliminal stimulus presentation of sexual stimuli could be a new approach to reduce vulnerability to manipulation. Meaningful images and scrambled images were applied as masks. Recognition performance was low, but interestingly, sexual preference and explicitness modulated stimulus visibility, suggesting interactions between networks of sexual arousal and consciousness. With scrambled masks, higher activations for sexually preferred images and for explicit images were found in areas associated with sexual arousal (Stoleru, Fonteille, Cornelis, Joyal, & Moulier, 2012). We conclude that masked sexual stimuli can evoke activations in areas associated with supraliminal induced sexual arousal. Copyright © 2017 Elsevier Inc. All rights reserved.

Continuity from an implicit to an explicit understanding of false belief from infancy to preschool age.

PubMed

Thoermer, Claudia; Sodian, Beate; Vuori, Maria; Perst, Hannah; Kristen, Susanne

2012-03-01

An implicit understanding of false belief indicated by anticipatory looking has been shown to be significantly correlated with performance on explicit false-belief tasks in 3- and 4-year-old children (Low, 2010). Recent evidence from infant research indicates, however, that implicit false-belief understanding guides infants' expectations about goal-directed actions even in the second year of life. The present study presents data from a sample of N= 70 infants who were tested longitudinally at 15, 18, 30, 36 and 48 months with implicit and explicit Theory of Mind measures, as well as an assessment of verbal IQ. Belief-based anticipatory looking in the false-belief task at 18 months significantly predicted verbal false-belief reasoning at 48 months, after controlling for verbal IQ. These findings indicate developmental continuity and conceptual specificity in belief reasoning from infancy to preschool age. They are discussed with respect to competing accounts of infants' understanding of the mind. © 2011 The British Psychological Society.

Interidentity memory transfer in dissociative identity disorder.

PubMed

Kong, Lauren L; Allen, John J B; Glisky, Elizabeth L

2008-08-01

Controversy surrounding dissociative identity disorder (DID) has focused on conflicting findings regarding the validity and nature of interidentity amnesia, illustrating the need for objective methods of examining amnesia that can discriminate between explicit and implicit memory transfer. In the present study, the authors used a cross-modal manipulation designed to mitigate implicit memory effects. Explicit memory transfer between identities was examined in 7 DID participants and 34 matched control participants. After words were presented to one identity auditorily, the authors tested another identity for memory of those words in the visual modality using an exclusion paradigm. Despite self-reported interidentity amnesia, memory for experimental stimuli transferred between identities. DID patients showed no superior ability to compartmentalize information, as would be expected with interidentity amnesia. The cross-modal nature of the test makes it unlikely that memory transfer was implicit. These findings demonstrate that subjective reports of interidentity amnesia are not necessarily corroborated by objective tests of explicit memory transfer. Copyright (c) 2008 APA, all rights reserved.

Chained Aggregation and Control System Design:; A Geometric Approach.

DTIC Science & Technology

1982-10-01

Furthermore, it explicitly identifies a reduced order modal used to meet the design goals. This results in an interactive design pro- cedure which allows...same framework. This leads directly to dynamic compen- sator design. The results are applied to decentralized control problems, non interactive ...goals. Furthermore, it explicitly identifies a reduced order model used to meet the design goals. This results in an interactive design procedure which

Effects of electrostatic interactions on ligand dissociation kinetics

NASA Astrophysics Data System (ADS)

Erbaş, Aykut; de la Cruz, Monica Olvera; Marko, John F.

2018-02-01

We study unbinding of multivalent cationic ligands from oppositely charged polymeric binding sites sparsely grafted on a flat neutral substrate. Our molecular dynamics simulations are suggested by single-molecule studies of protein-DNA interactions. We consider univalent salt concentrations spanning roughly a 1000-fold range, together with various concentrations of excess ligands in solution. To reveal the ionic effects on unbinding kinetics of spontaneous and facilitated dissociation mechanisms, we treat electrostatic interactions both at a Debye-Hückel (DH) (or implicit ions, i.e., use of an electrostatic potential with a prescribed decay length) level and by the more precise approach of considering all ionic species explicitly in the simulations. We find that the DH approach systematically overestimates unbinding rates, relative to the calculations where all ion pairs are present explicitly in solution, although many aspects of the two types of calculation are qualitatively similar. For facilitated dissociation (FD) (acceleration of unbinding by free ligands in solution) explicit-ion simulations lead to unbinding at lower free-ligand concentrations. Our simulations predict a variety of FD regimes as a function of free-ligand and ion concentrations; a particularly interesting regime is at intermediate concentrations of ligands where nonelectrostatic binding strength controls FD. We conclude that explicit-ion electrostatic modeling is an essential component to quantitatively tackle problems in molecular ligand dissociation, including nucleic-acid-binding proteins.

Working memory moderates the effect of the integrative process of implicit and explicit autonomous motivation on academic achievement.

PubMed

Gareau, Alexandre; Gaudreau, Patrick

2017-11-01

In previous research, autonomous motivation (AM) has been found to be associated with school achievement, but the relation has been largely heterogeneous across studies. AM has typically been assessed with explicit measures such as self-report questionnaires. Recent self-determination theory (SDT) research has suggested that converging implicit and explicit measures can be taken to characterize the integrative process in SDT. Drawing from dual-process theories, we contended that explicit AM is likely to promote school achievement when it is part of an integrated cognitive system that combines easily accessible mental representations (i.e., implicit AM) and efficient executive functioning. A sample of 272 university students completed a questionnaire and a lexical decision task to assess their explicit and implicit AM, respectively, and they also completed working memory capacity measures. Grades were obtained at the end of the semester to examine the short-term prospective effect of implicit and explicit AM, working memory, and their interaction. Results of moderation analyses have provided support for a synergistic interaction in which the association between explicit AM and academic achievement was positive and significant only for individuals with high level of implicit AM. Moreover, working memory was moderating the synergistic effect of explicit and implicit AM. Explicit AM was positively associated with academic achievement for students with average-to-high levels of working memory capacity, but only if their motivation operated synergistically with high implicit AM. The integrative process thus seems to hold better proprieties for achievement than the sole effect of explicit AM. Implications for SDT are outlined. © 2017 The British Psychological Society.

Face puzzle—two new video-based tasks for measuring explicit and implicit aspects of facial emotion recognition

PubMed Central

Kliemann, Dorit; Rosenblau, Gabriela; Bölte, Sven; Heekeren, Hauke R.; Dziobek, Isabel

2013-01-01

Recognizing others' emotional states is crucial for effective social interaction. While most facial emotion recognition tasks use explicit prompts that trigger consciously controlled processing, emotional faces are almost exclusively processed implicitly in real life. Recent attempts in social cognition suggest a dual process perspective, whereby explicit and implicit processes largely operate independently. However, due to differences in methodology the direct comparison of implicit and explicit social cognition has remained a challenge. Here, we introduce a new tool to comparably measure implicit and explicit processing aspects comprising basic and complex emotions in facial expressions. We developed two video-based tasks with similar answer formats to assess performance in respective facial emotion recognition processes: Face Puzzle, implicit and explicit. To assess the tasks' sensitivity to atypical social cognition and to infer interrelationship patterns between explicit and implicit processes in typical and atypical development, we included healthy adults (NT, n = 24) and adults with autism spectrum disorder (ASD, n = 24). Item analyses yielded good reliability of the new tasks. Group-specific results indicated sensitivity to subtle social impairments in high-functioning ASD. Correlation analyses with established implicit and explicit socio-cognitive measures were further in favor of the tasks' external validity. Between group comparisons provide first hints of differential relations between implicit and explicit aspects of facial emotion recognition processes in healthy compared to ASD participants. In addition, an increased magnitude of between group differences in the implicit task was found for a speed-accuracy composite measure. The new Face Puzzle tool thus provides two new tasks to separately assess explicit and implicit social functioning, for instance, to measure subtle impairments as well as potential improvements due to social cognitive interventions. PMID:23805122

Spin-orbit splitted excited states using explicitly-correlated equation-of-motion coupled-cluster singles and doubles eigenvectors

NASA Astrophysics Data System (ADS)

Bokhan, Denis; Trubnikov, Dmitrii N.; Perera, Ajith; Bartlett, Rodney J.

2018-04-01

An explicitly-correlated method of calculation of excited states with spin-orbit couplings, has been formulated and implemented. Developed approach utilizes left and right eigenvectors of equation-of-motion coupled-cluster model, which is based on the linearly approximated explicitly correlated coupled-cluster singles and doubles [CCSD(F12)] method. The spin-orbit interactions are introduced by using the spin-orbit mean field (SOMF) approximation of the Breit-Pauli Hamiltonian. Numerical tests for several atoms and molecules show good agreement between explicitly-correlated results and the corresponding values, calculated in complete basis set limit (CBS); the highly-accurate excitation energies can be obtained already at triple- ζ level.

Improve Student Understanding Ability Through Gamification in Instructional Media Based Explicit Instruction

NASA Astrophysics Data System (ADS)

Firdausi, N.; Prabawa, H. W.; Sutarno, H.

2017-02-01

In an effort to maximize a student’s academic growth, one of the tools available to educators is the explicit instruction. Explicit instruction is marked by a series of support or scaffold, where the students will be guided through the learning process with a clear statement of purpose and a reason for learning new skills, a clear explanation and demonstration of learning targets, supported and practiced with independent feedback until mastery has been achieved. The technology development trend of todays, requires an adjustment in the development of learning object that supports the achievement of explicit instruction targets. This is where the gamification position is. In the role as a pedagogical strategy, the use of gamification preformance study class is still relatively new. Gamification not only use the game elements and game design techniques in non-game contexts, but also to empower and engage learners with the ability of motivation on learning approach and maintains a relaxed atmosphere. With using Reseach and Development methods, this paper presents the integration of technology (which in this case using the concept of gamification) in explicit instruction settings and the impact on the improvement of students’ understanding.

Follow your nose: Implicit spatial processing within the chemosensory systems.

PubMed

Wudarczyk, Olga A; Habel, Ute; Turetsky, Bruce I; Gur, Raquel E; Kellermann, Thilo; Schneider, Frank; Moessnang, Carolin

2016-11-01

Although most studies agree that humans cannot smell in stereo, it was recently suggested that olfactory localization is possible when assessed implicitly. In a spatial cueing paradigm, lateralized olfactory cues impaired the detection of congruently presented visual targets, an effect contrary to the typical facilitation observed in other sensory domains. Here, we examined the specificity and the robustness of this finding by studying implicit localization abilities in another chemosensory system and by accounting for possible confounds in a modified paradigm. Sixty participants completed a spatial cueing task along with an explicit localization task, using trigeminal (Experiment 1) and olfactory (Experiment 2) stimuli. A control task was implemented to control for residual somatosensory stimulation (Experiment 3). In the trigeminal experiment, stimuli were localized with high accuracy on the explicit level, while the cueing effect in form of facilitation was limited to response accuracy. In the olfactory experiment, responses were slowed by congruent cues on the implicit level, while no explicit localization was observed. Our results point to the robustness of the olfactory interference effect, corroborating the implicit-explicit dissociation of olfactory localization, and challenging the view that humans lost the ability to extract spatial information from smell. The absence of a similar interference for trigeminal cues suggests distinct implicit spatial processing mechanisms within the chemosensory systems. Moreover, the lack of a typical facilitation effect in the trigeminal domain points to important differences from spatial information processing in other, nonchemosensory domains. The possible mechanisms driving the effects are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

How to aggregate health? Separability and the effect of framing.

PubMed

Turpcu, Adam; Bleichrodt, Han; Le, Quang A; Doctor, Jason N

2012-01-01

Unweighted summation or quality-adjusted life year (QALY) utilitarianism is the most common way to aggregate health benefits in a cost-effectiveness analysis. A key qualitative principle underlying QALY utilitarianism is separability: those individuals unaffected by a policy choice should not influence the policy choice. Separability also underlies several of the alternatives for QALY utilitarianism that have been proposed. To test separability and to test whether the support for separability is affected by the framing of the choice questions. In 2 experiments, 345 student subjects (162 in the first experiment, and 183 in the second experiment) were asked to select 1 of 2 possible treatments, with each treatment resulting in a different distribution of health across individuals. The only aspect that varied across choice questions was the state of the patients whose health was unaffected by the act of choosing a policy. In each experiment, we used 2 frames. In the implicit frame, it was implied but not plainly expressed what outcomes the treatments had in common. In the explicit frame, common outcomes of the 2 treatments were directly stated. The 2 experiments differed in the way the explicit frame was presented (verbal v. numerical). The support for separability was significantly greater in the explicit frame. The proportion of violations in the implicit frame was 44% in Experiment 1 and 31% in Experiment 2, while in the explicit frame, the proportion of violations was 28% in Experiment 1 and 8% in Experiment 2. Framing affected the support for separability, raising issues as to whether it is possible to achieve a canonical representation of social choices.

Assessment of multireference approaches to explicitly correlated full configuration interaction quantum Monte Carlo

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

Kersten, J. A. F., E-mail: jennifer.kersten@cantab.net; Alavi, Ali, E-mail: a.alavi@fkf.mpg.de; Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart

2016-08-07

The Full Configuration Interaction Quantum Monte Carlo (FCIQMC) method has proved able to provide near-exact solutions to the electronic Schrödinger equation within a finite orbital basis set, without relying on an expansion about a reference state. However, a drawback to the approach is that being based on an expansion of Slater determinants, the FCIQMC method suffers from a basis set incompleteness error that decays very slowly with the size of the employed single particle basis. The FCIQMC results obtained in a small basis set can be improved significantly with explicitly correlated techniques. Here, we present a study that assesses andmore » compares two contrasting “universal” explicitly correlated approaches that fit into the FCIQMC framework: the [2]{sub R12} method of Kong and Valeev [J. Chem. Phys. 135, 214105 (2011)] and the explicitly correlated canonical transcorrelation approach of Yanai and Shiozaki [J. Chem. Phys. 136, 084107 (2012)]. The former is an a posteriori internally contracted perturbative approach, while the latter transforms the Hamiltonian prior to the FCIQMC simulation. These comparisons are made across the 55 molecules of the G1 standard set. We found that both methods consistently reduce the basis set incompleteness, for accurate atomization energies in small basis sets, reducing the error from 28 mE{sub h} to 3-4 mE{sub h}. While many of the conclusions hold in general for any combination of multireference approaches with these methodologies, we also consider FCIQMC-specific advantages of each approach.« less

Types of high self-esteem and prejudice: how implicit self-esteem relates to ethnic discrimination among high explicit self-esteem individuals.

PubMed

Jordan, Christian H; Spencer, Steven J; Zanna, Mark P

2005-05-01

There is increasing recognition that high self-esteem is heterogeneous. Recent research suggests that individuals who report having high self-esteem (i.e., have high explicit self-esteem) behave more defensively to the extent that they have relatively low implicit self-esteem. The current studies test whether individuals with high explicit self-esteem are more likely to discriminate ethnically, as a defensive technique, to the extent that they have relatively low implicit self-esteem. The results support this prediction. Among participants with high explicit self-esteem, all of whom were threatened by negative performance feedback, those with relatively low implicit self-esteem recommended a more severe punishment for a Native, but not a White, student who started a fist-fight. In Study 2, this pattern was not apparent for participants with relatively low explicit self-esteem.

The role of attention during encoding in implicit and explicit memory.

PubMed

Mulligan, N W

1998-01-01

In 5 experiments, participants read study words under conditions of divided or full attention. Dividing attention reduced performance on the general knowledge test, a conceptual implicit test of memory. Likewise, dividing attention reduced conceptual priming on the word--association task, as well as on a matched explicit test, associate-cued recall. In contrast, even very strong division of attention did not reduce perceptual priming on word-fragment completion, although it did reduce recall on the matched explicit test of word-fragment-cued recall. Finally, dividing attention reduced recall on the perceptual explicit tests of graphemic-cued recall and graphemic recognition. The results indicate that perceptual implicit tests rely minimally on attention-demanding encoding processes relative to other types of memory tests. The obtained pattern of dissociations is not readily accommodated by the transfer-appropriate-processing (TAP) account of implicit and explicit memory. Potential extensions of the TAP view are discussed.

When Flexibility Is Stable: Implicit Long-Term Shaping of Olfactory Preferences

PubMed Central

Coppin, Géraldine; Delplanque, Sylvain; Porcherot, Christelle; Cayeux, Isabelle; Sander, David

2012-01-01

Preferences are traditionally assumed to be stable. However, empirical evidence such as preference modulation following choices calls this assumption into question. The evolution of such postchoice preference over long time spans, even when choices have been explicitly forgotten, has so far not been studied. In two experiments, we investigated this question by using a variant of the free choice paradigm: In a first session, participants evaluated the pleasantness of a number of odors. We then formed pairs of similarly rated odors, and asked participants to choose their favorite, for each pair. Participants were then presented with all odors again, and asked for another pleasantness rating. In a second session 1 week later, a third pleasantness rating was obtained, and participants were again asked to choose between the same options. Results suggested postchoice preference modulation immediately and 1 week after choice for both chosen and rejected options, even when choices were not explicitly remembered. A third experiment, using another paradigm, confirmed that choice can have a modulatory impact on preferences, and that this modulation can be long-lasting. Taken together, these findings suggest that although preferences appear to be flexible because they are modulated by choices, this modulation also appears to be stable over time and even without explicit recollection of the choice. These results bring a new argument to the idea that postchoice preference modulation could rely on implicit mechanisms, and are consistent with the recent proposal that cognitive dissonance reduction could to some extent be implicit. PMID:22761661

Low Cloud Feedback to Surface Warming in the World's First Global Climate Model with Explicit Embedded Boundary Layer Turbulence

NASA Astrophysics Data System (ADS)

Parishani, H.; Pritchard, M. S.; Bretherton, C. S.; Wyant, M. C.; Khairoutdinov, M.; Singh, B.

2017-12-01

Biases and parameterization formulation uncertainties in the representation of boundary layer clouds remain a leading source of possible systematic error in climate projections. Here we show the first results of cloud feedback to +4K SST warming in a new experimental climate model, the ``Ultra-Parameterized (UP)'' Community Atmosphere Model, UPCAM. We have developed UPCAM as an unusually high-resolution implementation of cloud superparameterization (SP) in which a global set of cloud resolving arrays is embedded in a host global climate model. In UP, the cloud-resolving scale includes sufficient internal resolution to explicitly generate the turbulent eddies that form marine stratocumulus and trade cumulus clouds. This is computationally costly but complements other available approaches for studying low clouds and their climate interaction, by avoiding parameterization of the relevant scales. In a recent publication we have shown that UP, while not without its own complexity trade-offs, can produce encouraging improvements in low cloud climatology in multi-month simulations of the present climate and is a promising target for exascale computing (Parishani et al. 2017). Here we show results of its low cloud feedback to warming in multi-year simulations for the first time. References: Parishani, H., M. S. Pritchard, C. S. Bretherton, M. C. Wyant, and M. Khairoutdinov (2017), Toward low-cloud-permitting cloud superparameterization with explicit boundary layer turbulence, J. Adv. Model. Earth Syst., 9, doi:10.1002/2017MS000968.

Matrix elements of N-particle explicitly correlated Gaussian basis functions with complex exponential parameters

NASA Astrophysics Data System (ADS)

Bubin, Sergiy; Adamowicz, Ludwik

2006-06-01

In this work we present analytical expressions for Hamiltonian matrix elements with spherically symmetric, explicitly correlated Gaussian basis functions with complex exponential parameters for an arbitrary number of particles. The expressions are derived using the formalism of matrix differential calculus. In addition, we present expressions for the energy gradient that includes derivatives of the Hamiltonian integrals with respect to the exponential parameters. The gradient is used in the variational optimization of the parameters. All the expressions are presented in the matrix form suitable for both numerical implementation and theoretical analysis. The energy and gradient formulas have been programed and used to calculate ground and excited states of the He atom using an approach that does not involve the Born-Oppenheimer approximation.

Matrix elements of N-particle explicitly correlated Gaussian basis functions with complex exponential parameters.

PubMed

Bubin, Sergiy; Adamowicz, Ludwik

2006-06-14

In this work we present analytical expressions for Hamiltonian matrix elements with spherically symmetric, explicitly correlated Gaussian basis functions with complex exponential parameters for an arbitrary number of particles. The expressions are derived using the formalism of matrix differential calculus. In addition, we present expressions for the energy gradient that includes derivatives of the Hamiltonian integrals with respect to the exponential parameters. The gradient is used in the variational optimization of the parameters. All the expressions are presented in the matrix form suitable for both numerical implementation and theoretical analysis. The energy and gradient formulas have been programmed and used to calculate ground and excited states of the He atom using an approach that does not involve the Born-Oppenheimer approximation.

Does the nature of science influence college students' learning of biological evolution?

NASA Astrophysics Data System (ADS)

Butler, Wilbert, Jr.

This quasi-experimental, mixed-methods study assessed the influence of the nature of science (NOS) instruction on college students' learning of biological evolution. In this research, conducted in two introductory biology courses, in each course the same instruction was employed, with one important exception: in the experimental section students were involved in an explicit, reflective treatment of the nature of science (Explicit, reflective NOS), in the traditional treatment section, NOS was implicitly addressed (traditional treatment). In both sections, NOS aspects of science addressed included is tentative, empirically based, subjective, inferential, and based on relationship between scientific theories and laws. Students understanding of evolution, acceptance of evolution, and understanding of the nature of science were assessed before, during and after instruction. Data collection entailed qualitative and quantitative methods including Concept Inventory for Natural Selection (CINS), Measure of Acceptance of the Theory of Evolution (MATE) survey, Views of nature of Science (VNOS-B survey), as well as interviews, classroom observations, and journal writing to address understand students' views of science and understanding and acceptance of evolution. The quantitative data were analyzed via inferential statistics and the qualitative data were analyzed using grounded theory. The data analysis allowed for the construction and support for four assertions: Assertion 1: Students engaged in explicit and reflective NOS specific instruction significantly improved their understanding of the nature of science concepts. Alternatively, students engaged in instruction using an implicit approach to the nature of science did not improve their understanding of the nature of science to the same degree. The VNOS-B results indicated that students in the explicit, reflective NOS class showed the better understanding of the NOS after the course than students in the implicit NOS class. The increased understanding of NOS demonstrated by students in the explicit, reflective NOS class compared to students in the implicit NOS class can be attributed to the students' engagement in explicit and reflective NOS instruction that was absent in the implicit NOS class. Post VNOS results from students in the explicit, reflective NOS class showed marked improvement in the targeted aspects of NOS (empirical nature of scientific knowledge, inferential nature of scientific knowledge, subjective nature of scientific knowledge, the distinction between scientific law and theory, and the tentative nature of scientific knowledge) compared to the result of the pretest while the scores of students in the implicit NOS class demonstrated little change. Assertion 2: Students in the explicit, reflective NOS class section made greater gains in their understanding of evolution than students in the traditional class. The explicit, reflective NOS class demonstrated a statistically significant improvement in their understanding of biological evolution after the course, while the changes observed in the implicit NOS group were not found to be statistically significant---this despite that the manner in which evolution was taught was held constant across the two sections. Thus, the explicit, reflective NOS approach to the teaching of biological evolution seems to be more effective than many discussed in the literature in supporting student learning about evolution. Assertion 3: The conceptual gains by students in the explicit, reflective NOS course section were allowed by the affective "room" that a sophisticated understanding of the nature of the nature of science provides in a classroom. The data collected from this study collectively indicate that a sophisticated understanding of NOS allows students to recognize the boundaries of science. We argue that an explicit and reflective engagement of the NOS aspects helps the students understand the defining aspects of science better. Assertion 4: A change in students' understanding of evolution does not necessitate a change in students' acceptance of evolution. The results showed that students engaged in explicit and reflective NOS specific instruction significantly improved their understanding of NOS concepts and the understanding of evolution. However, there was not a significant change in acceptance of evolution related to the change in understanding. These results demonstrate that the nature of science instruction plays an important role in the teaching and learning of biological evolution. Nevertheless, this NOS instruction must be explicit and reflective in nature. Students that engage explicitly and reflectively on specific tenets of NOS not only developed a better understanding of the NOS aspects but also a better understanding of biological evolution. Therefore, science teachers in elementary, middle, secondary and post-secondary education should consider implementing an explicit, reflective approach to the nature of science into their science curriculum not only for teaching evolution but for other controversial topics as well. (Abstract shortened by UMI.)

The Brain's Reward Response Occurs Even Without Actual Reward!

PubMed

Fielding, A; Fu, Y; Franz, E A

2018-06-01

What if the brain's response to reward occurs even when there is no reward? Wouldn't that be a further concern for people prone to problem gambling and other forms of addiction, like those related to eating? Electroencephalography was employed to investigate this possibility using probabilistic feedback manipulations and measures of known event-related potentials (ERPs) related to reward processing. We tested the hypothesis-that reward-based ERPs would occur even in the absence of a tangible reward and when manipulations on expectation are implicit. The well-known P300 response potential was a key focus, and was assessed in non-gambling volunteer undergraduates on a task involving experimentally-manipulated probabilities of positive or negative feedback comprising three trial types-80, 50, or 20% positive feedback. A feedback stimulus (F1) followed a guess response between two possible outcomes (implicit win/loss), and then a second feedback stimulus (F2) was presented to confirm an alleged 'win' or 'loss' (explicit win/loss). Results revealed that amplitude of the P300 in F1-locked data (implicit manipulation) was larger (more positive) on average for feedback outcomes that were manipulated to be less likely than expected. The effect is pronounced after increased time on task (later trials), even though the majority of participants were not explicitly aware of our probability manipulations. For the explicit effects in F2-locked data, no meaningful or significant effects were observed. These findings point to the existence of proposed success-response mechanisms that operate not only explicitly but also with implicit manipulations that do not involve any direct indication of a win or loss, and are not associated with tangible rewards. Thus, there seems to be a non-explicit form of perception (we call 'implicit') associated with an internal experience of wins/losses (in the absence of actual rewards or losses) that can be measured in associated brain processes. The potential significance of these findings is discussed in terms of implications for problem gambling.

Flavour chemicals in a sample of non-cigarette tobacco products without explicit flavour names sold in New York City in 2015.

PubMed

Farley, Shannon M; Schroth, Kevin Rj; Grimshaw, Victoria; Luo, Wentai; DeGagne, Julia L; Tierney, Peyton A; Kim, Kilsun; Pankow, James F

2018-03-01

Youth who experiment with tobacco often start with flavoured products. In New York City (NYC), local law restricts sales of all tobacco products with 'characterising flavours' except for 'tobacco, menthol, mint and wintergreen'. Enforcement is based on packaging: explicit use of a flavour name (eg, 'strawberry') or image depicting a flavour (eg, a fruit) is presumptive evidence that a product is flavoured and therefore prohibited. However, a tobacco product may contain significant levels of added flavour chemicals even when the label does not explicitly use a flavour name. Sixteen tobacco products were purchased within NYC in 2015 that did not have explicit flavour names, along with three with flavour names. These were analysed for 92 known flavour chemicals plus triacetin by gas chromatography/mass spectrometry. 14 of the 16 products had total determined flavour chemical levels that were higher (>0.3 mg/g) than in previously studied flavour-labelled products and of a chemical profile indicating added flavour chemicals. The results suggest that the tobacco industry has responded to sales restrictions by renaming flavoured products to avoid explicitly identifying them as flavoured. While chemical analysis is the most precise means of identifying flavours in tobacco products, federal tobacco laws pre-empt localities from basing regulations on that approach, limiting enforcement options. If the Food and Drug Administration would mandate that all tobacco products must indicate when flavourings are present above a specific level, local jurisdictions could enforce their sales restrictions. A level of 0.1 mg/g for total added flavour chemicals is suggested here as a relevant reference value for regulating added flavour chemicals in tobacco products. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The Reception Learning Paradigm.

ERIC Educational Resources Information Center

Novak, Joseph D.

1979-01-01

Presented is a paradigm for science education research. The paradigm advances the reception learning theory, where regularities to be learned are presented explicitly to the learner. A tool for the study of knowledge production in science education, the Gowin "V," is presented. (RE)

Student perceptions regarding the usefulness of explicit discussion of "Structure of the Observed Learning Outcome" taxonomy.

PubMed

Prakash, E S; Narayan, K A; Sethuraman, K R

2010-09-01

One method of grading responses of the descriptive type is by using Structure of Observed Learning Outcomes (SOLO) taxonomy. The basis of this study was the expectation that if students were oriented to SOLO taxonomy, it would provide them an opportunity to understand some of the factors that teachers consider while grading descriptive responses and possibly develop strategies to improve scores. We first sampled the perceptions of 68 second-year undergraduate medical students doing the Respiratory System course regarding the usefulness of explicit discussion of SOLO taxonomy. Subsequently, in a distinct cohort of 20 second-year medical students doing the Central Nervous System course, we sought to determine whether explicit illustration of SOLO taxonomy combined with some advice on better answering descriptive test questions (to an experimental group) resulted in better student scores in a continuous assessment test compared with providing advice for better answering test questions but without any reference to SOLO taxonomy (the control group). Student ratings of the clarity of the presentation on SOLO taxonomy appeared satisfactory to the authors, as was student understanding of our presentation. The majority of participants indicated that knowledge of SOLO taxonomy would help them study and prepare better answers for questions of the descriptive type. Although scores in the experimental and control group were comparable, this experience nonetheless provided us with the motivation to orient students to SOLO taxonomy early on in the medical program and further research factors that affect students' development of strategies based on knowledge of SOLO taxonomy.

Thalamic volume deficit contributes to procedural and explicit memory impairment in HIV infection with primary alcoholism comorbidity.

PubMed

Fama, Rosemary; Rosenbloom, Margaret J; Sassoon, Stephanie A; Rohlfing, Torsten; Pfefferbaum, Adolf; Sullivan, Edith V

2014-12-01

Component cognitive and motor processes contributing to diminished visuomotor procedural learning in HIV infection with comorbid chronic alcoholism (HIV+ALC) include problems with attention and explicit memory processes. The neural correlates associated with this constellation of cognitive and motor processes in HIV infection and alcoholism have yet to be delineated. Frontostriatal regions are affected in HIV infection, frontothalamocerebellar regions are affected in chronic alcoholism, and frontolimbic regions are likely affected in both; all three of these systems have the potential of contributing to both visuomotor procedural learning and explicit memory processes. Here, we examined the neural correlates of implicit memory, explicit memory, attention, and motor tests in 26 HIV+ALC (5 with comorbidity for nonalcohol drug abuse/dependence) and 19 age-range matched healthy control men. Parcellated brain volumes, including cortical, subcortical, and allocortical regions, as well as cortical sulci and ventricles, were derived using the SRI24 brain atlas. Results indicated that smaller thalamic volumes were associated with poorer performance on tests of explicit (immediate and delayed) and implicit (visuomotor procedural) memory in HIV+ALC. By contrast, smaller hippocampal volumes were associated with lower scores on explicit, but not implicit memory. Multiple regression analyses revealed that volumes of both the thalamus and the hippocampus were each unique independent predictors of explicit memory scores. This study provides evidence of a dissociation between implicit and explicit memory tasks in HIV+ALC, with selective relationships observed between hippocampal volume and explicit but not implicit memory, and highlights the relevance of the thalamus to mnemonic processes.

Continuum Fatigue Damage Modeling for Use in Life Extending Control

NASA Technical Reports Server (NTRS)

Lorenzo, Carl F.

1994-01-01

This paper develops a simplified continuum (continuous wrp to time, stress, etc.) fatigue damage model for use in Life Extending Controls (LEC) studies. The work is based on zero mean stress local strain cyclic damage modeling. New nonlinear explicit equation forms of cyclic damage in terms of stress amplitude are derived to facilitate the continuum modeling. Stress based continuum models are derived. Extension to plastic strain-strain rate models are also presented. Application of these models to LEC applications is considered. Progress toward a nonzero mean stress based continuum model is presented. Also, new nonlinear explicit equation forms in terms of stress amplitude are also derived for this case.

Implicit schemes and parallel computing in unstructured grid CFD

NASA Technical Reports Server (NTRS)

Venkatakrishnam, V.

1995-01-01

The development of implicit schemes for obtaining steady state solutions to the Euler and Navier-Stokes equations on unstructured grids is outlined. Applications are presented that compare the convergence characteristics of various implicit methods. Next, the development of explicit and implicit schemes to compute unsteady flows on unstructured grids is discussed. Next, the issues involved in parallelizing finite volume schemes on unstructured meshes in an MIMD (multiple instruction/multiple data stream) fashion are outlined. Techniques for partitioning unstructured grids among processors and for extracting parallelism in explicit and implicit solvers are discussed. Finally, some dynamic load balancing ideas, which are useful in adaptive transient computations, are presented.

Spatial abundance models and seasonal distribution for guanaco (Lama guanicoe) in central Tierra del Fuego, Argentina.

PubMed

Flores, Celina E; Deferrari, Guillermo; Collado, Leonardo; Escobar, Julio; Schiavini, Adrián

2018-01-01

Spatially explicit modelling allows to estimate population abundance and predict species' distribution in relation to environmental factors. Abiotic factors are the main determinants of a herbivore´s response to environmental heterogeneity on large spatiotemporal scales. We assessed the influence of elevation, geographic location and distance to the coast on the seasonal abundance and distribution of guanaco (Lama guanicoe) in central Tierra del Fuego, by means of spatially explicit modelling. The estimated abundance was 23,690 individuals for the non-breeding season and 33,928 individuals for the breeding season. The factors influencing distribution and abundance revealed to be the elevation for the non-breeding season, and the distance to the coast and geographic location for the breeding season. The southwest of the study area presented seasonal abundance variation and the southeast and northeast presented high abundance during both seasons. The elevation would be the driving factor of guanaco distribution, as individuals move to lower areas during the non-breeding season and ascend to high areas during the breeding season. Our results confirm that part of the guanaco population performs seasonal migratory movements and that the main valleys present important wintering habitats for guanacos as well as up-hill zones during summer. This type of study would help to avoid problems of scale mismatch and achieve better results in management actions and is an example of how to assess important seasonal habitats from evaluations of abundance and distribution patterns.

Spatial abundance models and seasonal distribution for guanaco (Lama guanicoe) in central Tierra del Fuego, Argentina

PubMed Central

Deferrari, Guillermo; Collado, Leonardo; Escobar, Julio; Schiavini, Adrián

2018-01-01

Spatially explicit modelling allows to estimate population abundance and predict species’ distribution in relation to environmental factors. Abiotic factors are the main determinants of a herbivore´s response to environmental heterogeneity on large spatiotemporal scales. We assessed the influence of elevation, geographic location and distance to the coast on the seasonal abundance and distribution of guanaco (Lama guanicoe) in central Tierra del Fuego, by means of spatially explicit modelling. The estimated abundance was 23,690 individuals for the non-breeding season and 33,928 individuals for the breeding season. The factors influencing distribution and abundance revealed to be the elevation for the non-breeding season, and the distance to the coast and geographic location for the breeding season. The southwest of the study area presented seasonal abundance variation and the southeast and northeast presented high abundance during both seasons. The elevation would be the driving factor of guanaco distribution, as individuals move to lower areas during the non-breeding season and ascend to high areas during the breeding season. Our results confirm that part of the guanaco population performs seasonal migratory movements and that the main valleys present important wintering habitats for guanacos as well as up-hill zones during summer. This type of study would help to avoid problems of scale mismatch and achieve better results in management actions and is an example of how to assess important seasonal habitats from evaluations of abundance and distribution patterns. PMID:29782523

Modeling of fatigue crack induced nonlinear ultrasonics using a highly parallelized explicit local interaction simulation approach

NASA Astrophysics Data System (ADS)

Shen, Yanfeng; Cesnik, Carlos E. S.

2016-04-01

This paper presents a parallelized modeling technique for the efficient simulation of nonlinear ultrasonics introduced by the wave interaction with fatigue cracks. The elastodynamic wave equations with contact effects are formulated using an explicit Local Interaction Simulation Approach (LISA). The LISA formulation is extended to capture the contact-impact phenomena during the wave damage interaction based on the penalty method. A Coulomb friction model is integrated into the computation procedure to capture the stick-slip contact shear motion. The LISA procedure is coded using the Compute Unified Device Architecture (CUDA), which enables the highly parallelized supercomputing on powerful graphic cards. Both the explicit contact formulation and the parallel feature facilitates LISA's superb computational efficiency over the conventional finite element method (FEM). The theoretical formulations based on the penalty method is introduced and a guideline for the proper choice of the contact stiffness is given. The convergence behavior of the solution under various contact stiffness values is examined. A numerical benchmark problem is used to investigate the new LISA formulation and results are compared with a conventional contact finite element solution. Various nonlinear ultrasonic phenomena are successfully captured using this contact LISA formulation, including the generation of nonlinear higher harmonic responses. Nonlinear mode conversion of guided waves at fatigue cracks is also studied.

Discrimination of tonal and atonal music in congenital amusia: The advantage of implicit tasks.

PubMed

Tillmann, Barbara; Lalitte, Philippe; Albouy, Philippe; Caclin, Anne; Bigand, Emmanuel

2016-05-01

Congenital amusia is a neurodevelopmental disorder of music perception and production, which has been attributed to a major deficit in pitch processing. While most studies and diagnosis tests have used explicit investigation methods, recent studies using implicit investigation approaches have revealed some unimpaired pitch structure processing in congenital amusia. The present study investigated amusic individuals' processing of tonal structures (e.g., musical structures respecting the Western tonal system) via three different questions. Amusic participants and their matched controls judged tonal versions (original musical excerpts) and atonal versions (with manipulated pitch content to remove tonal structures) of 12 musical pieces. For each piece, participants answered three questions that required judgments from different perspectives: an explicit structural one, a personal, emotional one and a more social one (judging the perception of others). Results revealed that amusic individuals' judgments differed between tonal and atonal versions. However, the question type influenced the extent of the revealed structure processing: while amusic individuals were impaired for the question requiring explicit structural judgments, they performed as well as their matched controls for the two other questions. Together with other recent studies, these findings suggest that congenital amusia might be related to a disorder of the conscious access to music processing rather than music processing per se. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pilot evaluation of parental and professional views regarding consent in neonatal medicine by telephone interviews and questionnaires

PubMed Central

2017-01-01

Objective The objectives of the study were to determine (1) parental and professional views regarding the type of consent required for common neonatal interventions and (2) whether there has been a change in professional understanding regarding the requirements of consent since the last UK survey in 2003. Design Cohort study of (1) parents of babies admitted to a single-centre tertiary neonatal unit and (2) healthcare professionals. Methods The views of 8 parents of former neonatal patients and 69 neonatal professionals were sought using online and telephone survey methodology regarding 20 neonatal interventions and whether implied consent, explicit verbal consent or explicit written consent should be obtained. Results Agreement, defined as both parental and professional consensus on the type of consent required, was present in 12/20 of the interventions. Comparison between professional views in 2003 demonstrated a change regarding type of consent for 50% of interventions with a shift towards obtaining explicit written consent certain treatments. Conclusions The study indicates areas of consensus that exist between parents and professionals regarding consent for common neonatal interventions and a change in professional views regarding consent since the last UK survey in 2003. These data might help inform the development of national guidance for how professionals should obtain consent in neonatology. PMID:29637148

Implicit and explicit self-esteem in remitted depressed patients.

PubMed

Smeijers, Danique; Vrijsen, Janna N; van Oostrom, Iris; Isaac, Linda; Speckens, Anne; Becker, Eni S; Rinck, Mike

2017-03-01

Low self-esteem is a symptom of depression and depression vulnerability. Prior research on self-esteem has largely focused on implicit (ISE) and explicit self-esteem (ESE) as two separate constructs, missing their interaction. Therefore, the current study investigated the interaction between ISE and ESE in a depression-vulnerable group (remitted depressed patients; RDs), compared to never-depressed controls (ND). Seventy-five RDs and 75 NDs participated in the study. To measure ESE, the Rosenberg Self-Esteem Scale (RSES) was used. The Implicit Association Test (IAT) and the Name Letter Preference Task (NLPT) were used to assess ISE. RDs reported lower ESE than NDs. However, the two groups did not differ on ISE. RDs exhibited a damaged self-esteem or a low-congruent self-esteem, similar to what has been found in currently depressed patients. Moreover, damaged self-esteem was associated with residual depressive symptoms. The results need to be interpreted with care because the IAT and NLPT did not reveal the same associations with the clinical measures. Implicit and explicit self-esteem may be different constructs in depression and studying the combination is important. The present study provides evidence indicating that damaged self-esteem may be more detrimental than low congruent self-esteem. Copyright © 2016 Elsevier Ltd. All rights reserved.

Deception dissociates from false belief reasoning in deaf children: implications for the implicit versus explicit theory of mind distinction.

PubMed

de Villiers, Peter A; de Villiers, Jill G

2012-03-01

Deception is a controversial aspect of theory of mind, and researchers disagree about whether it entails an understanding of the false beliefs of one's opponent. The present study asks whether children with delayed language and delayed explicit false belief reasoning can succeed on explicit deception tasks. Participants were 45 orally taught deaf children with varying language delays aged 4.5-8 years and 45 hearing children aged 3.5-6 years. Participants received a battery of language, executive function, deception, and both verbal and low-verbal false belief tasks. The result reveal a dissociation of deception and false belief tasks: the deaf children are on par with their hearing peers on deception games, but show significant delays in false belief tasks even when the language demands are made minimal. Furthermore, different skills are predictors of success for the two types of task in the deaf children: language, and in particular complement syntax, is the best predictor of false belief reasoning; but executive function skills, especially inhibitory control, are the best predictors of deception. It is argued that deception at this level can be handled by behaviour rules without reference to mental states. © 2011 The British Psychological Society.

False belief understanding in Cantonese-speaking children.

PubMed

Tardif, Twila; Wellman, Henry M; Cheung, Kar Man

2004-11-01

The present study investigates the performance of 96 Cantonese-speaking three- to five-year-old preschoolers on three false belief tasks - a deceptive object, a change of location, and an unexpected contents task encompassing a variety of task factors. Most importantly, the research examines the possibility that false belief performance depends on specific linguistic factors such as the type of verb used in the test question--an explicitly false vs. a neutral belief verb. Cantonese was chosen as particularly useful for examining this question because it explicitly codes belief status as either neutral (nam5) or false (ji5wai4), and because it offers additional linguistic and cultural contrasts to research conducted on false belief with children learning English and other Indo-European languages. As expected, a strong age effect was found, as well as a significant advantage for children who received the explicit false belief (ji5wai4) wording and for those who were asked to explain rather than predict the protagonist's actions. Interestingly, there was also a strong task difference with children performing better on the deceptive object task than on the other two false belief tasks. We argue that these results point both to universal trajectories in theory of mind development and to interesting, but localized, effects of language and culture on children's false belief understanding.

The Impact of Experience on Affective Responses during Action Observation.

PubMed

Kirsch, Louise P; Snagg, Arielle; Heerey, Erin; Cross, Emily S

2016-01-01

Perceiving others in action elicits affective and aesthetic responses in observers. The present study investigates the extent to which these responses relate to an observer's general experience with observed movements. Facial electromyographic (EMG) responses were recorded in experienced dancers and non-dancers as they watched short videos of movements performed by professional ballet dancers. Responses were recorded from the corrugator supercilii (CS) and zygomaticus major (ZM) muscles, both of which show engagement during the observation of affect-evoking stimuli. In the first part of the experiment, participants passively watched the videos while EMG data were recorded. In the second part, they explicitly rated how much they liked each movement. Results revealed a relationship between explicit affective judgments of the movements and facial muscle activation only among those participants who were experienced with the movements. Specifically, CS activity was higher for disliked movements and ZM activity was higher for liked movements among dancers but not among non-dancers. The relationship between explicit liking ratings and EMG data in experienced observers suggests that facial muscles subtly echo affective judgments even when viewing actions that are not intentionally emotional in nature, thus underscoring the potential of EMG as a method to examine subtle shifts in implicit affective responses during action observation.

Altered Medial Frontal and Superior Temporal Response to Implicit Processing of Emotions in Autism.

PubMed

Kana, Rajesh K; Patriquin, Michelle A; Black, Briley S; Channell, Marie M; Wicker, Bruno

2016-01-01

Interpreting emotional expressions appropriately poses a challenge for individuals with autism spectrum disorder (ASD). In particular, difficulties with emotional processing in ASD are more pronounced in contexts where emotional expressions are subtle, automatic, and reflexive-that is, implicit. In contrast, explicit emotional processing, which requires the cognitive evaluation of an emotional experience, appears to be relatively intact in individuals with ASD. In the present study, we examined the brain activation and functional connectivity differences underlying explicit and implicit emotional processing in age- and IQ-matched adults with (n = 17) and without (n = 15) ASD. Results indicated: (1) significantly reduced levels of brain activation in participants with ASD in medial prefrontal cortex (MPFC) and superior temporal gyrus (STG) during implicit emotion processing; (2) significantly weaker functional connectivity in the ASD group in connections of the MPFC with the amygdala, temporal lobe, parietal lobe, and fusiform gyrus; (3) No group difference in performance accuracy or reaction time; and (4) Significant positive relationship between empathizing ability and STG activity in ASD but not in typically developing participants. These findings suggest that the neural mechanisms underlying implicit, but not explicit, emotion processing may be altered at multiple levels in individuals with ASD. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

A robust and high precision optimal explicit guidance scheme for solid motor propelled launch vehicles with thrust and drag uncertainty

NASA Astrophysics Data System (ADS)

Maity, Arnab; Padhi, Radhakant; Mallaram, Sanjeev; Mallikarjuna Rao, G.; Manickavasagam, M.

2016-10-01

A new nonlinear optimal and explicit guidance law is presented in this paper for launch vehicles propelled by solid motors. It can ensure very high terminal precision despite not having the exact knowledge of the thrust-time curve apriori. This was motivated from using it for a carrier launch vehicle in a hypersonic mission, which demands an extremely narrow terminal accuracy window for the launch vehicle for successful initiation of operation of the hypersonic vehicle. The proposed explicit guidance scheme, which computes the optimal guidance command online, ensures the required stringent final conditions with high precision at the injection point. A key feature of the proposed guidance law is an innovative extension of the recently developed model predictive static programming guidance with flexible final time. A penalty function approach is also followed to meet the input and output inequality constraints throughout the vehicle trajectory. In this paper, the guidance law has been successfully validated from nonlinear six degree-of-freedom simulation studies by designing an inner-loop autopilot as well, which enhances confidence of its usefulness significantly. In addition to excellent nominal results, the proposed guidance has been found to have good robustness for perturbed cases as well.

[Priority setting and bedside rationing: a discussion of empirical findings].

PubMed

Strech, Daniel

2011-01-01

In addition to empirical forecasts on the extent of the current and future limitations on health care resources, empirical data on the status quo of bedside rationing play a significant role in developing suitable alternatives in dealing with limited financial resources. This article presents and discusses selected results of the international and German survey research on bedside rationing. Survey studies among physicians could prove world-wide that rationing decisions are made already today by individual physicians in the in- and out-patient services. In German hospitals, rationing is also a wide-spread though non-transparent and not (yet) very common phenomenon for an individual physician. Varying criteria for bedside rationing contribute to the fact that the current approach to bedside rationing leads to dissatisfaction on the part of physicians and to a potential disadvantage of certain patient groups. Explicit, i.e. transparent and systematic, ways of rationing could remedy these deficiencies and are therefore clearly preferable in this context. However, further specification of the methods of explicit rationing and a critical evaluation of their application in practice are needed. Moreover, it is mainly the quality of the underlying evidence that determines whether or not the actual decisions become more reasonable and fair by means of more explicit rationing approaches. Copyright © 2011 S. Karger AG, Basel.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Morality constrains the default representation of what is possible.

PubMed

Phillips, Jonathan; Cushman, Fiery

2017-05-02

The capacity for representing and reasoning over sets of possibilities, or modal cognition, supports diverse kinds of high-level judgments: causal reasoning, moral judgment, language comprehension, and more. Prior research on modal cognition asks how humans explicitly and deliberatively reason about what is possible but has not investigated whether or how people have a default, implicit representation of which events are possible. We present three studies that characterize the role of implicit representations of possibility in cognition. Collectively, these studies differentiate explicit reasoning about possibilities from default implicit representations, demonstrate that human adults often default to treating immoral and irrational events as impossible, and provide a case study of high-level cognitive judgments relying on default implicit representations of possibility rather than explicit deliberation.

Multidisciplinary Views on Applying Explicit and Implicit Motor Learning in Practice: An International Survey

PubMed Central

Kleynen, Melanie; Braun, Susy M.; Rasquin, Sascha M. C.; Bleijlevens, Michel H. C.; Lexis, Monique A. S.; Halfens, Jos; Wilson, Mark R.; Masters, Rich S. W.; Beurskens, Anna J.

2015-01-01

Background A variety of options and techniques for causing implicit and explicit motor learning have been described in the literature. The aim of the current paper was to provide clearer guidance for practitioners on how to apply motor learning in practice by exploring experts’ opinions and experiences, using the distinction between implicit and explicit motor learning as a conceptual departure point. Methods A survey was designed to collect and aggregate informed opinions and experiences from 40 international respondents who had demonstrable expertise related to motor learning in practice and/or research. The survey was administered through an online survey tool and addressed potential options and learning strategies for applying implicit and explicit motor learning. Responses were analysed in terms of consensus (≥ 70%) and trends (≥ 50%). A summary figure was developed to illustrate a taxonomy of the different learning strategies and options indicated by the experts in the survey. Results Answers of experts were widely distributed. No consensus was found regarding the application of implicit and explicit motor learning. Some trends were identified: Explicit motor learning can be promoted by using instructions and various types of feedback, but when promoting implicit motor learning, instructions and feedback should be restricted. Further, for implicit motor learning, an external focus of attention should be considered, as well as practicing the entire skill. Experts agreed on three factors that influence motor learning choices: the learner’s abilities, the type of task, and the stage of motor learning (94.5%; n = 34/36). Most experts agreed with the summary figure (64.7%; n = 22/34). Conclusion The results provide an overview of possible ways to cause implicit or explicit motor learning, signposting examples from practice and factors that influence day-to-day motor learning decisions. PMID:26296203

Neural correlates of erotic stimulation under different levels of female sexual hormones.

PubMed

Abler, Birgit; Kumpfmüller, Daniela; Grön, Georg; Walter, Martin; Stingl, Julia; Seeringer, Angela

2013-01-01

Previous studies have demonstrated variable influences of sexual hormonal states on female brain activation and the necessity to control for these in neuroimaging studies. However, systematic investigations of these influences, particularly those of hormonal contraceptives as compared to the physiological menstrual cycle are scarce. In the present study, we investigated the hormonal modulation of neural correlates of erotic processing in a group of females under hormonal contraceptives (C group; N = 12), and a different group of females (nC group; N = 12) not taking contraceptives during their mid-follicular and mid-luteal phases of the cycle. We used functional magnetic resonance imaging to measure hemodynamic responses as an estimate of brain activation during three different experimental conditions of visual erotic stimulation: dynamic videos, static erotic pictures, and expectation of erotic pictures. Plasma estrogen and progesterone levels were assessed in all subjects. No strong hormonally modulating effect was detected upon more direct and explicit stimulation (viewing of videos or pictures) with significant activations in cortical and subcortical brain regions previously linked to erotic stimulation consistent across hormonal levels and stimulation type. Upon less direct and less explicit stimulation (expectation), activation patterns varied between the different hormonal conditions with various, predominantly frontal brain regions showing significant within- or between-group differences. Activation in the precentral gyrus during the follicular phase in the nC group was found elevated compared to the C group and positively correlated with estrogen levels. From the results we conclude that effects of hormonal influences on brain activation during erotic stimulation are weak if stimulation is direct and explicit but that female sexual hormones may modulate more subtle aspects of sexual arousal and behaviour as involved in sexual expectation. Results may provide a basis for future imaging studies on sexual processing in females, especially in the context of less explicit erotic stimulation.

Neural Correlates of Erotic Stimulation under Different Levels of Female Sexual Hormones

PubMed Central

Abler, Birgit; Kumpfmüller, Daniela; Grön, Georg; Walter, Martin; Stingl, Julia; Seeringer, Angela

2013-01-01

Previous studies have demonstrated variable influences of sexual hormonal states on female brain activation and the necessity to control for these in neuroimaging studies. However, systematic investigations of these influences, particularly those of hormonal contraceptives as compared to the physiological menstrual cycle are scarce. In the present study, we investigated the hormonal modulation of neural correlates of erotic processing in a group of females under hormonal contraceptives (C group; N = 12), and a different group of females (nC group; N = 12) not taking contraceptives during their mid-follicular and mid-luteal phases of the cycle. We used functional magnetic resonance imaging to measure hemodynamic responses as an estimate of brain activation during three different experimental conditions of visual erotic stimulation: dynamic videos, static erotic pictures, and expectation of erotic pictures. Plasma estrogen and progesterone levels were assessed in all subjects. No strong hormonally modulating effect was detected upon more direct and explicit stimulation (viewing of videos or pictures) with significant activations in cortical and subcortical brain regions previously linked to erotic stimulation consistent across hormonal levels and stimulation type. Upon less direct and less explicit stimulation (expectation), activation patterns varied between the different hormonal conditions with various, predominantly frontal brain regions showing significant within- or between-group differences. Activation in the precentral gyrus during the follicular phase in the nC group was found elevated compared to the C group and positively correlated with estrogen levels. From the results we conclude that effects of hormonal influences on brain activation during erotic stimulation are weak if stimulation is direct and explicit but that female sexual hormones may modulate more subtle aspects of sexual arousal and behaviour as involved in sexual expectation. Results may provide a basis for future imaging studies on sexual processing in females, especially in the context of less explicit erotic stimulation. PMID:23418428

Reputation Management in Children on the Autism Spectrum.

PubMed

Cage, Eilidh; Bird, Geoffrey; Pellicano, Elizabeth

2016-12-01

Being able to manage reputation is an important social skill, but it is unclear whether autistic children can manage reputation. This study investigated whether 33 autistic children matched to 33 typical children could implicitly or explicitly manage reputation. Further, we examined whether cognitive processes-theory of mind, social motivation, inhibitory control and reciprocity-contribute to reputation management. Results showed that neither group implicitly managed reputation, and there was no group difference in explicit reputation management. Results suggested different mechanisms contribute to reputation management in these groups-social motivation in typical children and reciprocity in autistic children. Explicit reputation management is achievable for autistic children, and there are individual differences in its relationship to underlying cognitive processes.

Closed form solution for a double quantum well using Gröbner basis

NASA Astrophysics Data System (ADS)

Acus, A.; Dargys, A.

2011-07-01

Analytical expressions for the spectrum, eigenfunctions and dipole matrix elements of a square double quantum well (DQW) are presented for a general case when the potential in different regions of the DQW has different heights and the effective masses are different. This was achieved by using a Gröbner basis algorithm that allowed us to disentangle the resulting coupled polynomials without explicitly solving the transcendental eigenvalue equation.

Molecular orientation in a dielectric liquid-vapor interphase

NASA Astrophysics Data System (ADS)

Chacón, E.; Mederos, L.; Navascués, G.; Tarazona, P.

1985-04-01

The density functional theory of Chacón et al. is used to study the molecular orientation in an interphase of a weak dipolar fluid. Explicit expressions are obtained using standard perturbation techniques. Molecular orientation, local susceptibility, and the Gibbsean surface susceptibility are evaluated for a Stockmayer model of dipolar fluid. The effect of the surface structure on the bulk ferroelectric transition is discussed in the light of the present theory and the numerical results.

Triple collinear emissions in parton showers

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

Höche, Stefan; Prestel, Stefan

2017-10-01

A framework to include triple collinear splitting functions into parton showers is presented, and the implementation of flavor-changing NLO splitting kernels is discussed as a first application. The correspondence between the Monte-Carlo integration and the analytic computation of NLO DGLAP evolution kernels is made explicit for both timelike and spacelike parton evolution. Numerical simulation results are obtained with two independent implementations of the new algorithm, using the two independent event generation frameworks Pythia and Sherpa.

A Rigorous Framework for Optimization of Expensive Functions by Surrogates

NASA Technical Reports Server (NTRS)

Booker, Andrew J.; Dennis, J. E., Jr.; Frank, Paul D.; Serafini, David B.; Torczon, Virginia; Trosset, Michael W.

1998-01-01

The goal of the research reported here is to develop rigorous optimization algorithms to apply to some engineering design problems for which design application of traditional optimization approaches is not practical. This paper presents and analyzes a framework for generating a sequence of approximations to the objective function and managing the use of these approximations as surrogates for optimization. The result is to obtain convergence to a minimizer of an expensive objective function subject to simple constraints. The approach is widely applicable because it does not require, or even explicitly approximate, derivatives of the objective. Numerical results are presented for a 31-variable helicopter rotor blade design example and for a standard optimization test example.

Damaged Self-Esteem is Associated with Internalizing Problems.

PubMed

Creemers, Daan H M; Scholte, Ron H J; Engels, Rutger C M E; Prinstein, Mitchell J; Wiers, Reinout W

2013-01-01

Implicit and explicit self-esteem are assumed to be important factors in understanding the onset and maintenance of psychological problems. The current study aims to examine the association between implicit and explicit self-esteem and their interaction with depressive symptoms, suicidal ideation, and loneliness. Specifically, the relationship between the size and the direction of the discrepancy between implicit and explicit self-esteem with depressive symptoms, suicidal ideation, and loneliness were examined. Participants were 95 young female adults (M = 21.2 years, SD = 1.88) enrolled in higher education. We administered the IAT to assess implicit self-esteem, and the Rosenberg self-esteem scale to measure explicit self-esteem while psychological problems were assessed through self-reports. Results showed that discrepancies between implicit and explicit self-esteem were positively associated with depressive symptoms, suicidal ideation, and loneliness. In addition, the direction of the discrepancy was specifically relevant: damaged self-esteem (i.e., high implicit self-esteem and low explicit self-esteem) was consistently associated with increased levels of depressive symptoms, suicidal ideation, and loneliness. In contrast, defensive or fragile self-esteem (i.e., low implicit and high explicit self-esteem) was solely associated with loneliness. These findings provide further support that specifically damaged self-esteem is an important vulnerability marker for depressive symptoms, suicidal ideation, and loneliness.

Damaged Self-Esteem is Associated with Internalizing Problems

PubMed Central

Creemers, Daan H. M.; Scholte, Ron H. J.; Engels, Rutger C. M. E.; Prinstein, Mitchell J.; Wiers, Reinout W.

2013-01-01

Implicit and explicit self-esteem are assumed to be important factors in understanding the onset and maintenance of psychological problems. The current study aims to examine the association between implicit and explicit self-esteem and their interaction with depressive symptoms, suicidal ideation, and loneliness. Specifically, the relationship between the size and the direction of the discrepancy between implicit and explicit self-esteem with depressive symptoms, suicidal ideation, and loneliness were examined. Participants were 95 young female adults (M = 21.2 years, SD = 1.88) enrolled in higher education. We administered the IAT to assess implicit self-esteem, and the Rosenberg self-esteem scale to measure explicit self-esteem while psychological problems were assessed through self-reports. Results showed that discrepancies between implicit and explicit self-esteem were positively associated with depressive symptoms, suicidal ideation, and loneliness. In addition, the direction of the discrepancy was specifically relevant: damaged self-esteem (i.e., high implicit self-esteem and low explicit self-esteem) was consistently associated with increased levels of depressive symptoms, suicidal ideation, and loneliness. In contrast, defensive or fragile self-esteem (i.e., low implicit and high explicit self-esteem) was solely associated with loneliness. These findings provide further support that specifically damaged self-esteem is an important vulnerability marker for depressive symptoms, suicidal ideation, and loneliness. PMID:23565101

Explicit self-esteem mediates the relationship between implicit self-esteem and memory biases in major depression.

PubMed

Romero, Nuria; Sanchez, Alvaro; Vázquez, Carmelo; Valiente, Carmen

2016-08-30

This study examines the relationships between explicit and implicit self-esteem and self-referent memory biases in depression. We specifically tested the hypothesis that implicit self-esteem would influence depression-related memory biases via its association with explicit self-esteem. Self-esteem was assessed in patients with a current Major Depressive Disorder (MDD; n=38) and in a control group of participants who had never experienced depression (ND; n=40) by using explicit (Rosenberg Self-esteem Questionnaire) and implicit (Go/No-go Association Task) measures. A self-referent processing task of negative and positive adjectives was used to assess memory bias. Our analyses revealed that participants diagnosed with MDD showed lower levels of both explicit and implicit self-esteem in comparison to ND participants. MDD compared to ND participants also recalled a greater number of depressed self-referent adjectives and lower recall of positive self-referent information. Mediation analyses showed an indirect effect of explicit self-esteem on the relationship between implicit self-esteem and depression-related memory biases in the MDD group. These findings suggest an association between implicit and explicit self-esteem in depression that may result in negative cognitive processing, as reflected by self-referent memory biases. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Implicit and Explicit Representations of Hand Position in Tool Use

PubMed Central

Rand, Miya K.; Heuer, Herbert

2013-01-01

Understanding the interactions of visual and proprioceptive information in tool use is important as it is the basis for learning of the tool's kinematic transformation and thus skilled performance. This study investigated how the CNS combines seen cursor positions and felt hand positions under a visuo-motor rotation paradigm. Young and older adult participants performed aiming movements on a digitizer while looking at rotated visual feedback on a monitor. After each movement, they judged either the proprioceptively sensed hand direction or the visually sensed cursor direction. We identified asymmetric mutual biases with a strong visual dominance. Furthermore, we found a number of differences between explicit and implicit judgments of hand directions. The explicit judgments had considerably larger variability than the implicit judgments. The bias toward the cursor direction for the explicit judgments was about twice as strong as for the implicit judgments. The individual biases of explicit and implicit judgments were uncorrelated. Biases of these judgments exhibited opposite sequential effects. Moreover, age-related changes were also different between these judgments. The judgment variability was decreased and the bias toward the cursor direction was increased with increasing age only for the explicit judgments. These results indicate distinct explicit and implicit neural representations of hand direction, similar to the notion of distinct visual systems. PMID:23894307

Effective Medium Theories for Multicomponent Poroelastic Composites

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

Berryman, J G

2005-02-08

In Biot's theory of poroelasticity, elastic materials contain connected voids or pores and these pores may be filled with fluids under pressure. The fluid pressure then couples to the mechanical effects of stress or strain applied externally to the solid matrix. Eshelby's formula for the response of a single ellipsoidal elastic inclusion in an elastic whole space to a strain imposed at a distant boundary is a very well-known and important result in elasticity. Having a rigorous generalization of Eshelby's results valid for poroelasticity means that the hard part of Eshelby's work (in computing the elliptic integrals needed to evaluatemore » the fourth-rank tensors for inclusions shaped like spheres, oblate and prolate spheroids, needles and disks) can be carried over from elasticity to poroelasticity--and also thermoelasticity--with only relatively minor modifications. Effective medium theories for poroelastic composites such as rocks can then be formulated easily by analogy to well-established methods used for elastic composites. An identity analogous to Eshelby's classic result has been derived [Physical Review Letters 79:1142-1145 (1997)] for use in these more complex and more realistic problems in rock mechanics analysis. Descriptions of the application of this result as the starting point for new methods of estimation are presented, including generalizations of the coherent potential approximation (CPA), differential effective medium (DEM) theory, and two explicit schemes. Results are presented for estimating drained shear and bulk modulus, the Biot-Willis parameter, and Skempton's coefficient. Three of the methods considered appear to be quite reliable estimators, while one of the explicit schemes is found to have some undesirable characteristics.« less

Perturbative triples correction for local pair natural orbital based explicitly correlated CCSD(F12*) using Laplace transformation techniques.

PubMed

Schmitz, Gunnar; Hättig, Christof

2016-12-21

We present an implementation of pair natural orbital coupled cluster singles and doubles with perturbative triples, PNO-CCSD(T), which avoids the quasi-canonical triples approximation (T0) where couplings due to off-diagonal Fock matrix elements are neglected. A numerical Laplace transformation of the canonical expression for the perturbative (T) triples correction is used to avoid an I/O and storage bottleneck for the triples amplitudes. Results for a test set of reaction energies show that only very few Laplace grid points are needed to obtain converged energy differences and that PNO-CCSD(T) is a more robust approximation than PNO-CCSD(T0) with a reduced mean absolute deviation from canonical CCSD(T) results. We combine the PNO-based (T) triples correction with the explicitly correlated PNO-CCSD(F12*) method and investigate the use of specialized F12-PNOs in the conventional triples correction. We find that no significant additional errors are introduced and that PNO-CCSD(F12*)(T) can be applied in a black box manner.

Source misattributions and false recognition errors: examining the role of perceptual resemblance and imagery generation processes.

PubMed

Foley, Mary Ann; Bays, Rebecca Brooke; Foy, Jeffrey; Woodfield, Mila

2015-01-01

In three experiments, we examine the extent to which participants' memory errors are affected by the perceptual features of an encoding series and imagery generation processes. Perceptual features were examined by manipulating the features associated with individual items as well as the relationships among items. An encoding instruction manipulation was included to examine the effects of explicit requests to generate images. In all three experiments, participants falsely claimed to have seen pictures of items presented as words, committing picture misattribution errors. These misattribution errors were exaggerated when the perceptual resemblance between pictures and images was relatively high (Experiment 1) and when explicit requests to generate images were omitted from encoding instructions (Experiments 1 and 2). When perceptual cues made the thematic relationships among items salient, the level and pattern of misattribution errors were also affected (Experiments 2 and 3). Results address alternative views about the nature of internal representations resulting in misattribution errors and refute the idea that these errors reflect only participants' general impressions or beliefs about what was seen.

Visual Search Elicits the Electrophysiological Marker of Visual Working Memory

PubMed Central

Emrich, Stephen M.; Al-Aidroos, Naseem; Pratt, Jay; Ferber, Susanne

2009-01-01

Background Although limited in capacity, visual working memory (VWM) plays an important role in many aspects of visually-guided behavior. Recent experiments have demonstrated an electrophysiological marker of VWM encoding and maintenance, the contralateral delay activity (CDA), which has been shown in multiple tasks that have both explicit and implicit memory demands. Here, we investigate whether the CDA is evident during visual search, a thoroughly-researched task that is a hallmark of visual attention but has no explicit memory requirements. Methodology/Principal Findings The results demonstrate that the CDA is present during a lateralized search task, and that it is similar in amplitude to the CDA observed in a change-detection task, but peaks slightly later. The changes in CDA amplitude during search were strongly correlated with VWM capacity, as well as with search efficiency. These results were paralleled by behavioral findings showing a strong correlation between VWM capacity and search efficiency. Conclusions/Significance We conclude that the activity observed during visual search was generated by the same neural resources that subserve VWM, and that this activity reflects the maintenance of previously searched distractors. PMID:19956663

Recollective performance advantages for implicit memory tasks.

PubMed

Sheldon, Signy A M; Moscovitch, Morris

2010-10-01

A commonly held assumption is that processes underlying explicit and implicit memory are distinct. Recent evidence, however, suggests that they may interact more than previously believed. Using the remember-know procedure the current study examines the relation between recollection, a process thought to be exclusive to explicit memory, and performance on two implicit memory tasks, lexical decision and word stem completion. We found that, for both implicit tasks, words that were recollected were associated with greater priming effects than were words given a subsequent familiarity rating or words that had been studied but were not recognised (misses). Broadly, our results suggest that non-voluntary processes underlying explicit memory also benefit priming, a measure of implicit memory. More specifically, given that this benefit was due to a particular aspect of explicit memory (recollection), these results are consistent with some strength models of memory and with Moscovitch's (2008) proposal that recollection is a two-stage process, one rapid and unconscious and the other more effortful and conscious.

Implicit and explicit appraisals of the importance of intrusive thoughts.

PubMed

Teachman, Bethany A; Woody, Sheila R; Magee, Joshua C

2006-06-01

To evaluate cognitive theories of obsessions, the current study experimentally manipulated appraisals of the importance of intrusive thoughts. Undergraduate students (N = 156) completed measures of obsessive-compulsive disorder (OCD) symptoms and beliefs and were primed with a list of commonly reported unwanted thoughts. Participants were then informed that unwanted thoughts are either (1) significant and indicative of their personal values, or (2) meaningless, or participants (3) received no instructions about unwanted thoughts. Participants then completed implicit and explicit measures of self-evaluation and interpretations of their unwanted thoughts. Results indicated that the manipulation shifted implicit appraisals of unwanted thoughts in the expected direction, but not self-evaluations of morality or dangerousness. Interestingly, explicit self-esteem and beliefs about the significance of unwanted thoughts were associated with measures of OCD beliefs, whereas implicit self-evaluations of dangerousness were better predicted by the interaction of pre-existing OCD beliefs with the manipulation. Results are discussed in terms of divergent predictors of implicit and explicit responses to unwanted thoughts.

A specific implicit sequence learning deficit as an underlying cause of dyslexia? Investigating the role of attention in implicit learning tasks.

PubMed

Staels, Eva; Van den Broeck, Wim

2017-05-01

Recently, a general implicit sequence learning deficit was proposed as an underlying cause of dyslexia. This new hypothesis was investigated in the present study by including a number of methodological improvements, for example, the inclusion of appropriate control conditions. The second goal of the study was to explore the role of attentional functioning in implicit and explicit learning tasks. In a 2 × 2 within-subjects design 4 tasks were administered in 30 dyslexic and 38 control children: an implicit and explicit serial reaction time (RT) task and an implicit and explicit contextual cueing task. Attentional functioning was also administered. The entire learning curves of all tasks were analyzed using latent growth curve modeling in order to compare performances between groups and to examine the role of attentional functioning on the learning curves. The amount of implicit learning was similar for both groups. However, the dyslexic group showed slower RTs throughout the entire task. This group difference reduced and became nonsignificant after controlling for attentional functioning. Both implicit learning tasks, but none of the explicit learning tasks, were significantly affected by attentional functioning. Dyslexic children do not suffer from a specific implicit sequence learning deficit. The slower RTs of the dyslexic children throughout the entire implicit sequence learning process are caused by their comorbid attention problems and overall slowness. A key finding of the present study is that, in contrast to what was assumed for a long time, implicit learning relies on attentional resources, perhaps even more than explicit learning does. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Willed action, free will, and the stochastic neurodynamics of decision-making

PubMed Central

Rolls, Edmund T.

2012-01-01

It is shown that the randomness of the firing times of neurons in decision-making attractor neuronal networks that is present before the decision cues are applied can cause statistical fluctuations that influence the decision that will be taken. In this rigorous sense, it is possible to partially predict decisions before they are made. This raises issues about free will and determinism. There are many decision-making networks in the brain. Some decision systems operate to choose between gene-specified rewards such as taste, touch, and beauty (in for example the peacock's tail). Other processes capable of planning ahead with multiple steps held in working memory may require correction by higher order thoughts that may involve explicit, conscious, processing. The explicit system can allow the gene-specified rewards not to be selected or deferred. The decisions between the selfish gene-specified rewards, and the explicitly calculated rewards that are in the interests of the individual, the phenotype, may themselves be influenced by noise in the brain. When the explicit planning system does take the decision, it can report on its decision-making, and can provide a causal account rather than a confabulation about the decision process. We might use the terms “willed action” and “free will” to refer to the operation of the planning system that can think ahead over several steps held in working memory with which it can take explicit decisions. Reduced connectivity in some of the default mode cortical regions including the precuneus that are active during self-initiated action appears to be related to the reduction in the sense of self and agency, of causing willed actions, that can be present in schizophrenia. PMID:22973205

Are children conservative, liberal, or metacognitive? Preliminary evidence for the involvement of the distinctiveness heuristic in decision making.

PubMed

Geurten, Marie; Willems, Sylvie; Meulemans, Thierry

2015-04-01

The experiment tested whether young children are able to reduce their false recognition rate after distinctive encoding by implementing a strategic metacognitive rule. The participants, 72 children aged 4, 6, and 9 years, studied two lists of unrelated items. One of these lists was visually displayed (picture condition), whereas the other was presented auditorily (word condition). After each study phase, participants completed recognition tests. Finally, they answered questions about their explicit knowledge of the distinctive encoding effect. The results revealed that even the youngest children in our sample showed a smaller proportion of intrusions in the picture condition than in the word condition. Furthermore, the results of the signal detection analyses were consistent with the hypothesis that the lower rate of false recognitions after picture encoding results from the implementation of a conservative response criterion based on metacognitive expectations (distinctiveness heuristic). Moreover, the absence of correlation between children's explicit knowledge of the distinctiveness rule and their effective use of this metacognitive heuristic seems to indicate that its involvement in memory decisions could be mediated by implicit mechanisms. Copyright © 2015 Elsevier Inc. All rights reserved.

Online dating and conjugal bereavement.

PubMed

Young, Goldthwaite Dannagal; Caplan, Scott E

2010-08-01

This study examined self-presentation in the online dating profiles of 241 widowed and 280 divorced individuals between 18 and 40 years old. A content analysis of open-ended user-generated profiles assessed the presence or absence of various themes, including the user's marital status, the backstory of their lost relationship, and whether they engaged in sense-making regarding that lost relationship. Results indicated that about one-third of widowed individuals discussed their loss in their profiles. In addition, about one-third of the widowed profiles included explicit reference to a philosophy of life, and about 16% mentioned sense-making or cognitive reappraisals of their bereavement. Many profiles included some articulation of a vision of a future partnership. Results also revealed a significant correlation between widowed individuals including a backstory and their likelihood of exhibiting sense-making in their profiles. Finally, unlike the widowed users, divorcees provided much briefer mentions of their lost relationships, used less sense-making language, and were less likely to articulate an explicit vision of future partnerships. Overall, the results suggest that for widowed individuals, online dating sites may function as venues to explore their past experiences and engage in the construction of a post-loss identity or a post-loss "ideal self".

Alternative modeling methods for plasma-based Rf ion sources

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

Veitzer, Seth A., E-mail: veitzer@txcorp.com; Kundrapu, Madhusudhan, E-mail: madhusnk@txcorp.com; Stoltz, Peter H., E-mail: phstoltz@txcorp.com

Rf-driven ion sources for accelerators and many industrial applications benefit from detailed numerical modeling and simulation of plasma characteristics. For instance, modeling of the Spallation Neutron Source (SNS) internal antenna H{sup −} source has indicated that a large plasma velocity is induced near bends in the antenna where structural failures are often observed. This could lead to improved designs and ion source performance based on simulation and modeling. However, there are significant separations of time and spatial scales inherent to Rf-driven plasma ion sources, which makes it difficult to model ion sources with explicit, kinetic Particle-In-Cell (PIC) simulation codes. Inmore » particular, if both electron and ion motions are to be explicitly modeled, then the simulation time step must be very small, and total simulation times must be large enough to capture the evolution of the plasma ions, as well as extending over many Rf periods. Additional physics processes such as plasma chemistry and surface effects such as secondary electron emission increase the computational requirements in such a way that even fully parallel explicit PIC models cannot be used. One alternative method is to develop fluid-based codes coupled with electromagnetics in order to model ion sources. Time-domain fluid models can simulate plasma evolution, plasma chemistry, and surface physics models with reasonable computational resources by not explicitly resolving electron motions, which thereby leads to an increase in the time step. This is achieved by solving fluid motions coupled with electromagnetics using reduced-physics models, such as single-temperature magnetohydrodynamics (MHD), extended, gas dynamic, and Hall MHD, and two-fluid MHD models. We show recent results on modeling the internal antenna H{sup −} ion source for the SNS at Oak Ridge National Laboratory using the fluid plasma modeling code USim. We compare demonstrate plasma temperature equilibration in two-temperature MHD models for the SNS source and present simulation results demonstrating plasma evolution over many Rf periods for different plasma temperatures. We perform the calculations in parallel, on unstructured meshes, using finite-volume solvers in order to obtain results in reasonable time.« less

Alternative modeling methods for plasma-based Rf ion sources.

PubMed

Veitzer, Seth A; Kundrapu, Madhusudhan; Stoltz, Peter H; Beckwith, Kristian R C

2016-02-01

Rf-driven ion sources for accelerators and many industrial applications benefit from detailed numerical modeling and simulation of plasma characteristics. For instance, modeling of the Spallation Neutron Source (SNS) internal antenna H(-) source has indicated that a large plasma velocity is induced near bends in the antenna where structural failures are often observed. This could lead to improved designs and ion source performance based on simulation and modeling. However, there are significant separations of time and spatial scales inherent to Rf-driven plasma ion sources, which makes it difficult to model ion sources with explicit, kinetic Particle-In-Cell (PIC) simulation codes. In particular, if both electron and ion motions are to be explicitly modeled, then the simulation time step must be very small, and total simulation times must be large enough to capture the evolution of the plasma ions, as well as extending over many Rf periods. Additional physics processes such as plasma chemistry and surface effects such as secondary electron emission increase the computational requirements in such a way that even fully parallel explicit PIC models cannot be used. One alternative method is to develop fluid-based codes coupled with electromagnetics in order to model ion sources. Time-domain fluid models can simulate plasma evolution, plasma chemistry, and surface physics models with reasonable computational resources by not explicitly resolving electron motions, which thereby leads to an increase in the time step. This is achieved by solving fluid motions coupled with electromagnetics using reduced-physics models, such as single-temperature magnetohydrodynamics (MHD), extended, gas dynamic, and Hall MHD, and two-fluid MHD models. We show recent results on modeling the internal antenna H(-) ion source for the SNS at Oak Ridge National Laboratory using the fluid plasma modeling code USim. We compare demonstrate plasma temperature equilibration in two-temperature MHD models for the SNS source and present simulation results demonstrating plasma evolution over many Rf periods for different plasma temperatures. We perform the calculations in parallel, on unstructured meshes, using finite-volume solvers in order to obtain results in reasonable time.

Pulsar distances and the galactic distribution of free electrons

NASA Technical Reports Server (NTRS)

Taylor, J. H.; Cordes, J. M.

1993-01-01

The present quantitative model for Galactic free electron distribution abandons the assumption of axisymmetry and explicitly incorporates spiral arms; their shapes and locations are derived from existing radio and optical observations of H II regions. The Gum Nebula's dispersion-measure contributions are also explicitly modeled. Adjustable quantities are calibrated by reference to three different types of data. The new model is estimated to furnish distance estimates to known pulsars that are accurate to about 25 percent.

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

Wieder, William R.; Allison, Steven D.; Davidson, Eric A.

Microbes influence soil organic matter (SOM) decomposition and the long-term stabilization of carbon (C) in soils. We contend that by revising the representation of microbial processes and their interactions with the physicochemical soil environment, Earth system models (ESMs) may make more realistic global C cycle projections. Explicit representation of microbial processes presents considerable challenges due to the scale at which these processes occur. Thus, applying microbial theory in ESMs requires a framework to link micro-scale process-level understanding and measurements to macro-scale models used to make decadal- to century-long projections. Here, we review the diversity, advantages, and pitfalls of simulating soilmore » biogeochemical cycles using microbial-explicit modeling approaches. We present a roadmap for how to begin building, applying, and evaluating reliable microbial-explicit model formulations that can be applied in ESMs. Drawing from experience with traditional decomposition models we suggest: (1) guidelines for common model parameters and output that can facilitate future model intercomparisons; (2) development of benchmarking and model-data integration frameworks that can be used to effectively guide, inform, and evaluate model parameterizations with data from well-curated repositories; and (3) the application of scaling methods to integrate microbial-explicit soil biogeochemistry modules within ESMs. With contributions across scientific disciplines, we feel this roadmap can advance our fundamental understanding of soil biogeochemical dynamics and more realistically project likely soil C response to environmental change at global scales.« less

Error Generation in CATS-Based Agents

NASA Technical Reports Server (NTRS)

Callantine, Todd

2003-01-01

This research presents a methodology for generating errors from a model of nominally preferred correct operator activities, given a particular operational context, and maintaining an explicit link to the erroneous contextual information to support analyses. It uses the Crew Activity Tracking System (CATS) model as the basis for error generation. This report describes how the process works, and how it may be useful for supporting agent-based system safety analyses. The report presents results obtained by applying the error-generation process and discusses implementation issues. The research is supported by the System-Wide Accident Prevention Element of the NASA Aviation Safety Program.

Finite element formulation with embedded weak discontinuities for strain localization under dynamic conditions

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

Jin, Tao; Mourad, Hashem M.; Bronkhorst, Curt A.

Here, we present an explicit finite element formulation designed for the treatment of strain localization under highly dynamic conditions. We also used a material stability analysis to detect the onset of localization behavior. Finite elements with embedded weak discontinuities are employed with the aim of representing subsequent localized deformation accurately. The formulation and its algorithmic implementation are described in detail. Numerical results are presented to illustrate the usefulness of this computational framework in the treatment of strain localization under highly dynamic conditions, and to examine its performance characteristics in the context of two-dimensional plane-strain problems.

An algebraic structure of discrete-time biaffine systems

NASA Technical Reports Server (NTRS)

Tarn, T.-J.; Nonoyama, S.

1979-01-01

New results on the realization of finite-dimensional, discrete-time, internally biaffine systems are presented in this paper. The external behavior of such systems is described by multiaffine functions and the state space is constructed via Nerode equivalence relations. We prove that the state space is an affine space. An algorithm which amounts to choosing a frame for the affine space is presented. Our algorithm reduces in the linear and bilinear case to a generalization of algorithms existing in the literature. Explicit existence criteria for span-canonical realizations as well as an affine isomorphism theorem are given.

Finite element formulation with embedded weak discontinuities for strain localization under dynamic conditions

DOE PAGES

Jin, Tao; Mourad, Hashem M.; Bronkhorst, Curt A.; ...

2017-09-13

Here, we present an explicit finite element formulation designed for the treatment of strain localization under highly dynamic conditions. We also used a material stability analysis to detect the onset of localization behavior. Finite elements with embedded weak discontinuities are employed with the aim of representing subsequent localized deformation accurately. The formulation and its algorithmic implementation are described in detail. Numerical results are presented to illustrate the usefulness of this computational framework in the treatment of strain localization under highly dynamic conditions, and to examine its performance characteristics in the context of two-dimensional plane-strain problems.

THOR: an open-source exo-GCM

NASA Astrophysics Data System (ADS)

Grosheintz, Luc; Mendonça, João; Käppeli, Roger; Lukas Grimm, Simon; Mishra, Siddhartha; Heng, Kevin

2015-12-01

In this talk, I will present THOR, the first fully conservative, GPU-accelerated exo-GCM (general circulation model) on a nearly uniform, global grid that treats shocks and is non-hydrostatic. THOR will be freely available to the community as a standard tool.Unlike most GCMs THOR solves the full, non-hydrostatic Euler equations instead of the primitive equations. The equations are solved on a global three-dimensional icosahedral grid by a second order Finite Volume Method (FVM). Icosahedral grids are nearly uniform refinements of an icosahedron. We've implemented three different versions of this grid. FVM conserves the prognostic variables (density, momentum and energy) exactly and doesn't require a diffusion term (artificial viscosity) in the Euler equations to stabilize our solver. Historically FVM was designed to treat discontinuities correctly. Hence it excels at resolving shocks, including those present in hot exoplanetary atmospheres.Atmospheres are generally in near hydrostatic equilibrium. We therefore implement a well-balancing technique recently developed at the ETH Zurich. This well-balancing ensures that our FVM maintains hydrostatic equilibrium to machine precision. Better yet, it is able to resolve pressure perturbations from this equilibrium as small as one part in 100'000. It is important to realize that these perturbations are significantly smaller than the truncation error of the same scheme without well-balancing. If during the course of the simulation (due to forcing) the atmosphere becomes non-hydrostatic, our solver continues to function correctly.THOR just passed an important mile stone. We've implemented the explicit part of the solver. The explicit solver is useful to study instabilities or local problems on relatively short time scales. I'll show some nice properties of the explicit THOR. An explicit solver is not appropriate for climate study because the time step is limited by the sound speed. Therefore, we are working on the first fully implicit GCM. By ESS3, I hope to present results for the advection equation.THOR is part of the Exoclimes Simulation Platform (ESP), a set of open-source community codes for simulating and understanding the atmospheres of exoplanets. The ESP also includes tools for radiative transfer and retrieval (HELIOS), an opacity calculator (HELIOS-K), and a chemical kinetics solver (VULCAN). We expect to publicly release an initial version of THOR in 2016 on www.exoclime.org.

Catastrophic Disruption of Asteroids: First Simulations with Explicit Formation of Spinning Rigid and Semi-rigid Aggregates

NASA Astrophysics Data System (ADS)

Michel, Patrick; Richardson, D. C.

2007-10-01

We have made major improvements in simulations of asteroid disruption by computing explicitly aggregate formations during the gravitational reaccumulation of small fragments, allowing us to obtain information on their spin and shape. First results will be presented taking as examples asteroid families that we reproduced successfully with previous less sophisticated simulations. In the last years, we have simulated successfully the formation of asteroid families using a SPH hydrocode to compute the fragmentation following the impact of a projectile on the parent body, and the N-body code pkdgrav to compute the mutual interactions of the fragments. We found that fragments generated by the disruption of a km-size asteroid can have large enough masses to be attracted by each other during their ejection. Consequently, many reaccumulations take place. Eventually most large fragments correspond to gravitational aggregates formed by reaccumulation of smaller ones. Moreover, formation of satellites occurs around the largest and other big remnants. In these previous simulations, when fragments reaccumulate, they merge into a single sphere whose mass is the sum of their masses. Thus, no information is obtained on the actual shape of the aggregates, their spin, ... For the first time, we have now simulated the disruption of a family parent body by computing explicitly the formation of aggregates, along with the above-mentioned properties. Once formed these aggregates can interact and/or collide with each other and break up during their evolution. We will present these first simulations and their possible implications on properties of asteroids generated by disruption. Results can for instance be compared with data provided by the Japanese space mission Hayabusa of the asteroid Itokawa, a body now understood to be a reaccumulated fragment from a larger parent body. Acknowledgments: PM and DCR acknowledge supports from the French Programme National de Planétologie and grants NSF AST0307549&AST0708110.

A mediation model to explain decision making under conditions of risk among adolescents: the role of fluid intelligence and probabilistic reasoning.

PubMed

Donati, Maria Anna; Panno, Angelo; Chiesi, Francesca; Primi, Caterina

2014-01-01

This study tested the mediating role of probabilistic reasoning ability in the relationship between fluid intelligence and advantageous decision making among adolescents in explicit situations of risk--that is, in contexts in which information on the choice options (gains, losses, and probabilities) were explicitly presented at the beginning of the task. Participants were 282 adolescents attending high school (77% males, mean age = 17.3 years). We first measured fluid intelligence and probabilistic reasoning ability. Then, to measure decision making under explicit conditions of risk, participants performed the Game of Dice Task, in which they have to decide among different alternatives that are explicitly linked to a specific amount of gain or loss and have obvious winning probabilities that are stable over time. Analyses showed a significant positive indirect effect of fluid intelligence on advantageous decision making through probabilistic reasoning ability that acted as a mediator. Specifically, fluid intelligence may enhance ability to reason in probabilistic terms, which in turn increases the likelihood of advantageous choices when adolescents are confronted with an explicit decisional context. Findings show that in experimental paradigm settings, adolescents are able to make advantageous decisions using cognitive abilities when faced with decisions under explicit risky conditions. This study suggests that interventions designed to promote probabilistic reasoning, for example by incrementing the mathematical prerequisites necessary to reason in probabilistic terms, may have a positive effect on adolescents' decision-making abilities.

Implicit and explicit learning in schizophrenics treated with olanzapine and with classic neuroleptics.

PubMed

Stevens, Andreas; Schwarz, Jürgen; Schwarz, Benedikt; Ruf, Ilona; Kolter, Thomas; Czekalla, Joerg

2002-03-01

Novel and classic neuroleptics differ in their effects on limbic striatal/nucleus accumbens (NA) and prefrontal cortex (PFC) dopamine turnover, suggesting differential effects on implicit and explicit learning as well as on anhedonia. The present study investigates whether such differences can be demonstrated in a naturalistic sample of schizophrenic patients. Twenty-five inpatients diagnosed with DSM-IV schizophrenic psychosis and treated for at least 14 days with the novel neuroleptic olanzapine were compared with 25 schizophrenics taking classic neuroleptics and with 25 healthy controls, matched by age and education level. PFC/NA-dependent implicit learning was assessed by a serial reaction time task (SRTT) and compared with cerebellum-mediated classical eye-blink conditioning and explicit visuospatial memory. Anhedonia was measured with the Snaith-Hamilton-Pleasure Scale (SHAPS). Implicit (SRTT) and psychomotor speed, but not explicit (visuospatial) learning were superior in the olanzapine-treated group as compared to the patients on classic neuroleptics. Compared to healthy controls, olanzapine-treated schizophrenics showed similar implicit learning, but reduced explicit (visuospatial) memory performance. Acquisition of eyeblink conditioning was not different between the three groups. There was no difference with regard to anhedonia and SANS scores between the patients. Olanzapine seems to interfere less with unattended learning and motor speed than classical neuroleptics. In daily life, this may translate into better adaptation to a rapidly changing environment. The effects seem specific, as in explicit learning and eyeblink conditioning no difference to classic NL was found.

Development of a discrete gas-kinetic scheme for simulation of two-dimensional viscous incompressible and compressible flows.

PubMed

Yang, L M; Shu, C; Wang, Y

2016-03-01

In this work, a discrete gas-kinetic scheme (DGKS) is presented for simulation of two-dimensional viscous incompressible and compressible flows. This scheme is developed from the circular function-based GKS, which was recently proposed by Shu and his co-workers [L. M. Yang, C. Shu, and J. Wu, J. Comput. Phys. 274, 611 (2014)]. For the circular function-based GKS, the integrals for conservation forms of moments in the infinity domain for the Maxwellian function-based GKS are simplified to those integrals along the circle. As a result, the explicit formulations of conservative variables and fluxes are derived. However, these explicit formulations of circular function-based GKS for viscous flows are still complicated, which may not be easy for the application by new users. By using certain discrete points to represent the circle in the phase velocity space, the complicated formulations can be replaced by a simple solution process. The basic requirement is that the conservation forms of moments for the circular function-based GKS can be accurately satisfied by weighted summation of distribution functions at discrete points. In this work, it is shown that integral quadrature by four discrete points on the circle, which forms the D2Q4 discrete velocity model, can exactly match the integrals. Numerical results showed that the present scheme can provide accurate numerical results for incompressible and compressible viscous flows with roughly the same computational cost as that needed by the Roe scheme.

Extension of the KLI approximation toward the exact optimized effective potential.

PubMed

Iafrate, G J; Krieger, J B

2013-03-07

The integral equation for the optimized effective potential (OEP) is utilized in a compact form from which an accurate OEP solution for the spin-unrestricted exchange-correlation potential, Vxcσ, is obtained for any assumed orbital-dependent exchange-correlation energy functional. The method extends beyond the Krieger-Li-Iafrate (KLI) approximation toward the exact OEP result. The compact nature of the OEP equation arises by replacing the integrals involving the Green's function terms in the traditional OEP equation by an equivalent first-order perturbation theory wavefunction often referred to as the "orbital shift" function. Significant progress is then obtained by solving the equation for the first order perturbation theory wavefunction by use of Dalgarno functions which are determined from well known methods of partial differential equations. The use of Dalgarno functions circumvents the need to explicitly address the Green's functions and the associated problems with "sum over states" numerics; as well, the Dalgarno functions provide ease in dealing with inherent singularities arising from the origin and the zeros of the occupied orbital wavefunctions. The Dalgarno approach for finding a solution to the OEP equation is described herein, and a detailed illustrative example is presented for the special case of a spherically symmetric exchange-correlation potential. For the case of spherical symmetry, the relevant Dalgarno function is derived by direct integration of the appropriate radial equation while utilizing a user friendly method which explicitly treats the singular behavior at the origin and at the nodal singularities arising from the zeros of the occupied states. The derived Dalgarno function is shown to be an explicit integral functional of the exact OEP Vxcσ, thus allowing for the reduction of the OEP equation to a self-consistent integral equation for the exact exchange-correlation potential; the exact solution to this integral equation can be determined by iteration with the natural zeroth order correction given by the KLI exchange-correlation potential. Explicit analytic results are provided to illustrate the first order iterative correction beyond the KLI approximation. The derived correction term to the KLI potential explicitly involves spatially weighted products of occupied orbital densities in any assumed orbital-dependent exchange-correlation energy functional; as well, the correction term is obtained with no adjustable parameters. Moreover, if the equation for the exact optimized effective potential is further iterated, one can obtain the OEP as accurately as desired.

Extension of the KLI approximation toward the exact optimized effective potential

NASA Astrophysics Data System (ADS)

Iafrate, G. J.; Krieger, J. B.

2013-03-01

The integral equation for the optimized effective potential (OEP) is utilized in a compact form from which an accurate OEP solution for the spin-unrestricted exchange-correlation potential, Vxcσ, is obtained for any assumed orbital-dependent exchange-correlation energy functional. The method extends beyond the Krieger-Li-Iafrate (KLI) approximation toward the exact OEP result. The compact nature of the OEP equation arises by replacing the integrals involving the Green's function terms in the traditional OEP equation by an equivalent first-order perturbation theory wavefunction often referred to as the "orbital shift" function. Significant progress is then obtained by solving the equation for the first order perturbation theory wavefunction by use of Dalgarno functions which are determined from well known methods of partial differential equations. The use of Dalgarno functions circumvents the need to explicitly address the Green's functions and the associated problems with "sum over states" numerics; as well, the Dalgarno functions provide ease in dealing with inherent singularities arising from the origin and the zeros of the occupied orbital wavefunctions. The Dalgarno approach for finding a solution to the OEP equation is described herein, and a detailed illustrative example is presented for the special case of a spherically symmetric exchange-correlation potential. For the case of spherical symmetry, the relevant Dalgarno function is derived by direct integration of the appropriate radial equation while utilizing a user friendly method which explicitly treats the singular behavior at the origin and at the nodal singularities arising from the zeros of the occupied states. The derived Dalgarno function is shown to be an explicit integral functional of the exact OEP Vxcσ, thus allowing for the reduction of the OEP equation to a self-consistent integral equation for the exact exchange-correlation potential; the exact solution to this integral equation can be determined by iteration with the natural zeroth order correction given by the KLI exchange-correlation potential. Explicit analytic results are provided to illustrate the first order iterative correction beyond the KLI approximation. The derived correction term to the KLI potential explicitly involves spatially weighted products of occupied orbital densities in any assumed orbital-dependent exchange-correlation energy functional; as well, the correction term is obtained with no adjustable parameters. Moreover, if the equation for the exact optimized effective potential is further iterated, one can obtain the OEP as accurately as desired.

Implicit attitudes towards homosexuality: reliability, validity, and controllability of the IAT.

PubMed

Banse, R; Seise, J; Zerbes, N

2001-01-01

Two experiments were conducted to investigate the psychometric properties of an Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) that was adapted to measure implicit attitudes towards homosexuality. In a first experiment, the validity of the Homosexuality-IAT was tested using a known group approach. Implicit and explicit attitudes were assessed in heterosexual and homosexual men and women (N = 101). The results provided compelling evidence for the convergent and discriminant validity of the Homosexuality-IAT as a measure of implicit attitudes. No evidence was found for two alternative explanations of IAT effects (familiarity with stimulus material and stereotype knowledge). The internal consistency of IAT scores was satisfactory (alpha s > .80), but retest correlations were lower. In a second experiment (N = 79) it was shown that uninformed participants were able to fake positive explicit but not implicit attitudes. Discrepancies between implicit and explicit attitudes towards homosexuality could be partially accounted for by individual differences in the motivation to control prejudiced behavior, thus providing independent evidence for the validity of the implicit attitude measure. Neither explicit nor implicit attitudes could be changed by persuasive messages. The results of both experiments are interpreted as evidence for a single construct account of implicit and explicit attitudes towards homosexuality.

Effect of explicit dimension instruction on speech category learning

PubMed Central

Chandrasekaran, Bharath; Yi, Han-Gyol; Smayda, Kirsten E.; Maddox, W. Todd

2015-01-01

Learning non-native speech categories is often considered a challenging task in adulthood. This difficulty is driven by cross-language differences in weighting critical auditory dimensions that differentiate speech categories. For example, previous studies have shown that differentiating Mandarin tonal categories requires attending to dimensions related to pitch height and direction. Relative to native speakers of Mandarin, the pitch direction dimension is under-weighted by native English speakers. In the current study, we examined the effect of explicit instructions (dimension instruction) on native English speakers' Mandarin tone category learning within the framework of a dual-learning systems (DLS) model. This model predicts that successful speech category learning is initially mediated by an explicit, reflective learning system that frequently utilizes unidimensional rules, with an eventual switch to a more implicit, reflexive learning system that utilizes multidimensional rules. Participants were explicitly instructed to focus and/or ignore the pitch height dimension, the pitch direction dimension, or were given no explicit prime. Our results show that instruction instructing participants to focus on pitch direction, and instruction diverting attention away from pitch height resulted in enhanced tone categorization. Computational modeling of participant responses suggested that instruction related to pitch direction led to faster and more frequent use of multidimensional reflexive strategies, and enhanced perceptual selectivity along the previously underweighted pitch direction dimension. PMID:26542400

Reduced cognitive capacity impairs the malleability of older adults' negative attitudes to stigmatized individuals.

PubMed

Krendl, Anne C

2018-05-21

Although engaging explicit regulatory strategies may reduce negative bias toward outgroup members, these strategies are cognitively demanding and thus may not be effective for older adults (OA) who have reduced cognitive resources. The current study therefore examines whether individual differences in cognitive capacity disrupt OA' ability to explicitly regulate their bias to stigmatized individuals. Young and OA were instructed to explicitly regulate their negative bias toward stigmatized individuals by using an explicit reappraisal strategy. Regulatory success was assessed as a function of age and individual differences in cognitive capacity (Experiment 1). In Experiment 2, the role of executive function in implementing cognitive reappraisal strategies was examined by using a divided attention manipulation. Results from Experiment 1 revealed that individual differences in OA' cognitive capacity disrupted their ability to regulate their negative emotional response to stigma. In Experiment 2, it was found that dividing attention in young adults (YA) significantly reduced their regulatory success as compared to YA' regulatory capacity in the full attention condition. As expected, dividing YA' attention made their performance similar to OA with relatively preserved cognitive capacity. Together, the results from this study demonstrated that individual differences in cognitive capacity predicted OA' ability to explicitly regulate their negative bias to a range of stigmatized individuals.

Schwarzschild fuzzball and explicitly unitary Hawking radiation

NASA Astrophysics Data System (ADS)

Zeng, Ding-fang

2018-05-01

We provide a fuzzball picture for Schwarzschild black holes, in which matters and energy consisting the hole are not positioned on the central point exclusively but oscillate around there in a serial of eigen-modes, each of which features a special level of binding degrees and are quantum mechanically possible to be measured outside the horizon. By listing these modes explicitly for holes as large as 6Mpl, we find that their number increases exponentially with the area. Basing on these results, we construct a simple but explicitly unitary formulation of Hawking radiations.

Robust approximate optimal guidance strategies for aeroassisted orbital transfer missions

NASA Astrophysics Data System (ADS)

Ilgen, Marc R.

This thesis presents the application of game theoretic and regular perturbation methods to the problem of determining robust approximate optimal guidance laws for aeroassisted orbital transfer missions with atmospheric density and navigated state uncertainties. The optimal guidance problem is reformulated as a differential game problem with the guidance law designer and Nature as opposing players. The resulting equations comprise the necessary conditions for the optimal closed loop guidance strategy in the presence of worst case parameter variations. While these equations are nonlinear and cannot be solved analytically, the presence of a small parameter in the equations of motion allows the method of regular perturbations to be used to solve the equations approximately. This thesis is divided into five parts. The first part introduces the class of problems to be considered and presents results of previous research. The second part then presents explicit semianalytical guidance law techniques for the aerodynamically dominated region of flight. These guidance techniques are applied to unconstrained and control constrained aeroassisted plane change missions and Mars aerocapture missions, all subject to significant atmospheric density variations. The third part presents a guidance technique for aeroassisted orbital transfer problems in the gravitationally dominated region of flight. Regular perturbations are used to design an implicit guidance technique similar to the second variation technique but that removes the need for numerically computing an optimal trajectory prior to flight. This methodology is then applied to a set of aeroassisted inclination change missions. In the fourth part, the explicit regular perturbation solution technique is extended to include the class of guidance laws with partial state information. This methodology is then applied to an aeroassisted plane change mission using inertial measurements and subject to uncertainties in the initial value of the flight path angle. A summary of performance results for all these guidance laws is presented in the fifth part of this thesis along with recommendations for further research.