884 resultados para Knowledge, Theory of Skepticism


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Background: In the context of the established finding that theory-of-mind (ToM) growth is seriously delayed in late-signing deaf children, and some evidence of equivalent delays in those learning speech with conventional hearing aids, this study's novel contribution was to explore ToM development in deaf children with cochlear implants. Implants can substantially boost auditory acuity and rates of language growth. Despite the implant, there are often problems socialising with hearing peers and some language difficulties, lending special theoretical interest to the present comparative design. Methods: A total of 52 children aged 4 to 12 years took a battery of false belief tests of ToM. There were 26 oral deaf children, half with implants and half with hearing aids, evenly divided between oral-only versus sign-plus-oral schools. Comparison groups of age-matched high-functioning children with autism and younger hearing children were also included. Results: No significant ToM differences emerged between deaf children with implants and those with hearing aids, nor between those in oral-only versus sign-plus-oral schools. Nor did the deaf children perform any better on the ToM tasks than their age peers with autism. Hearing preschoolers scored significantly higher than all other groups. For the deaf and the autistic children, as well as the preschoolers, rate of language development and verbal maturity significantly predicted variability in ToM, over and above chronological age. Conclusions: The finding that deaf children with cochlear implants are as delayed in ToM development as children with autism and their deaf peers with hearing aids or late sign language highlights the likely significance of peer interaction and early fluent communication with peers and family, whether in sign or in speech, in order to optimally facilitate the growth of social cognition and language.

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The diagrammatic strong-coupling perturbation theory (SCPT) for correlated electron systems is developed for intersite Coulomb interaction and for a nonorthogonal basis set. The construction is based on iterations of exact closed equations for many - electron Green functions (GFs) for Hubbard operators in terms of functional derivatives with respect to external sources. The graphs, which do not contain the contributions from the fluctuations of the local population numbers of the ion states, play a special role: a one-to-one correspondence is found between the subset of such graphs for the many - electron GFs and the complete set of Feynman graphs of weak-coupling perturbation theory (WCPT) for single-electron GFs. This fact is used for formulation of the approximation of renormalized Fermions (ARF) in which the many-electron quasi-particles behave analogously to normal Fermions. Then, by analyzing: (a) Sham's equation, which connects the self-energy and the exchange- correlation potential in density functional theory (DFT); and (b) the Galitskii and Migdal expressions for the total energy, written within WCPT and within ARF SCPT, a way we suggest a method to improve the description of the systems with correlated electrons within the local density approximation (LDA) to DFT. The formulation, in terms of renormalized Fermions LIDA (RF LDA), is obtained by introducing the spectral weights of the many electron GFs into the definitions of the charge density, the overlap matrices, effective mixing and hopping matrix elements, into existing electronic structure codes, whereas the weights themselves have to be found from an additional set of equations. Compared with LDA+U and self-interaction correction (SIC) methods, RF LDA has the advantage of taking into account the transfer of spectral weights, and, when formulated in terms of GFs, also allows for consideration of excitations and nonzero temperature. Going beyond the ARF SCPT, as well as RF LIDA, and taking into account the fluctuations of ion population numbers would require writing completely new codes for ab initio calculations. The application of RF LDA for ab initio band structure calculations for rare earth metals is presented in part 11 of this study (this issue). (c) 2005 Wiley Periodicals, Inc.

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We have previously shown that a division of the f-shell into two subsystems gives a better understanding of the cohesive properties as well the general behavior of lanthanide systems. In this article, we present numerical computations, using the suggested method. We show that the picture is consistent with most experimental data, e.g., the equilibrium volume and electronic structure in general. Compared with standard energy band calculations and calculations based on the self-interaction correction and LIDA + U, the f-(non-f)-mixing interaction is decreased by spectral weights of the many-body states of the f-ion. (c) 2005 Wiley Periodicals, Inc.

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The mean abundances of Mg, Si, Ca, Ti, Cr, and Fe based on both strong and weak lines of alpha CenAare determined by matching the observed line profiles with those synthesised from stellar atmospheric models and comparing these results with a similar analysis for the Sun. There is good agreement between the abundances from strong and weak lines. Strong lines should generally be an excellent indicator of abundance and far easier to measure than the weak lines normally used. Until the development of the Anstee, Barklem, and O'Mara ( ABO) theory for collisional line broadening, the uncertainty in the value of the damping constant prevented strong lines being used for abundance determinations other than in close differential analyses. We found that alpha Cen A has a mean overabundance of 0.12 +/- 0.06 dex compared to solar mean abundances. This result agrees remarkably well with previous studies that did not use strong lines or the ABO theory for collisional line broadening. Our result supports the conclusion that reliable abundances can be derived from strong lines provided this new theory for line broadening is used to calculate the van derWaals damping.

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The authors argue that human desire involves conscious cognition that has strong affective connotation and is potentially involved in the determination of appetitive behavior rather than being epiphenomenal to it. Intrusive thoughts about appetitive targets are triggered automatically by external or physiological cues and by cognitive associates. When intrusions elicit significant pleasure or relief, cognitive elaboration usually ensues. Elaboration competes with concurrent cognitive tasks through retrieval of target-related information and its retention in working memory. Sensory images are especially important products of intrusion and elaboration because they simulate the sensory and emotional qualities of target acquisition. Desire images are momentarily rewarding but amplify awareness of somatic and emotional deficits. Effects of desires on behavior are moderated by competing incentives, target availability, and skills. The theory provides a coherent account of existing data and suggests new directions for research and treatment.

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A self-consistent theory is derived to describe the BCS-Bose-Einstein-condensate crossover for a strongly interacting Fermi gas with a Feshbach resonance. In the theory the fluctuation of the dressed molecules, consisting of both preformed Cooper pairs and bare Feshbach molecules, has been included within a self-consistent T-matrix approximation, beyond the Nozieres and Schmitt-Rink strategy considered by Ohashi and Griffin. The resulting self-consistent equations are solved numerically to investigate the normal-state properties of the crossover at various resonance widths. It is found that the superfluid transition temperature T-c increases monotonically at all widths as the effective interaction between atoms becomes more attractive. Furthermore, a residue factor Z(m) of the molecule's Green function and a complex effective mass have been determined to characterize the fraction and lifetime of Feshbach molecules at T-c. Our many-body calculations of Z(m) agree qualitatively well with recent measurments of the gas of Li-6 atoms near the broad resonance at 834 G. The crossover from narrow to broad resonances has also been studied.

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Two studies compared leader-member exchange (LMX) theory and the social identity theory of leadership. Study 1 surveyed 439 employees of organizations in Wales, measuring Work group salience, leader-member relations, and perceived leadership effectiveness. Study 2 surveyed 128 members of organizations in India, measuring identification not salience and also individualism/collectivism. Both studies provided good support for social identity predictions. Depersonalized leader-member relations were associated with greater leadership effectiveness among high- than low-salient groups (Study 1) and among high than low identifiers (Study 2). Personalized leadership effectiveness was less affected by salience (Study 1) and unaffected by identification (Study 2). Low-salience groups preferred personalized leadership more than did high-salience groups (Study 1). Low identifiers showed no preference but high identifiers preferred depersonalized leadership (Study 2). In Study 2, collectivists did not Prefer depersonalized as opposed to personalized leadership, whereas individualists did, probably because collectivists focus more on the relational self.

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This article presents three studies conducted in Canada and Australia that relate theory of mind (ToM) development to mental state discourse. In Study 1, mental state discourse was examined while parents and their 5-7-year-old children jointly read a storybook which had a surprise ending about the identity of the main character. Comments specific to the mental states of the story characters and discourse after the book had ended were positively related to children's ToM, and this was due to parent elaborations. Studies 2 and 3 examined children's mental state discourse during storytelling tasks, and in both, mental state discourse of children during narrative was concurrently related to ToM performance. While research has shown that mental state discourse of parents is related to children's ToM acquisition, the current research indicates that children's spontaneous use of mental state language examined outside of the interactional context is also a strong correlate.

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Prior research demonstrates that understanding theory of mind (ToM) is seriously and similarly delayed in late-signing deaf children and children with autism. Are these children simply delayed in timing relative to typical children, or do they demonstrate different patterns of development? The current research addressed this question by testing 145 children (ranging from 3 to 13 years) with deafness, autism, or typical development using a ToM scale. Results indicate that all groups followed the same sequence of steps, up to a point, but that children with autism showed an importantly different sequence of understandings (in the later steps of the progression) relative to all other groups.

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Theory of mind (ToM) was examined in late-signing deaf children in two studies by using standard tests and measures of spontaneous talk about inner states of perception, affect and cognition during storytelling. In Study 1, there were 21 deaf children aged 6 to 11 years and 13 typical-hearing children matched with the deaf by chronological age. In Study 2, there were 17 deaf children aged 6 to 12 years and 17 typical-hearing preschoolers aged 4 to 5 years who were matched with the deaf by ToM test performance. In addition to replicating the consistently reported finding of poor performance on standard false belief tests by late-signing deaf children, significant correlations emerged in both studies between deaf children's ToM test scores and their spontaneous narrative talk about imaginative cognition (e.g. 'pretend'). In Study 2, with a new set of purpose-built pictures that evoked richer and more complex mentalistic narration than the published picture book of Study 1, results of multiple regression analyses showed that children's narrative talk about imaginative cognition was uniquely important, over and above hearing status and talking of other kinds of mental states, in predicting ToM scores. The same was true of children's elaborated narrative talk using utterances that either spelt out thoughts, explained inner states or introduced contrastives. In addition, results of a Guttman scalograrn analysis in Study 2 suggested a consistent sequence in narrative and standard test performance by deaf and hearing children that went from (1) narrative mention of visible (affective or perceptual) mental states only, along with FB failure, to (2) narrative mention of cognitive states along with (1), to (3) elaborated narrative talk about inner states along with (2), and finally to (4) simple and elaborated narrative talk about affective/perceptual and cognitive states along with FIB test success. Possible explanations for this performance ordering, as well as for the observed correlations in both studies between ToM test scores and narrative variables, were considered.

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Through a prospective study of 70 youths staying at homeless-youth shelters, the authors tested the utility of I. Ajzen's (1991) theory of planned behavior (TPB), by comparing the constructs of self-efficacy with perceived behavioral control (PBC), in predicting people's rule-following behavior during shelter stays. They performed the 1st wave of data collection through a questionnaire assessing the standard TPB components of attitudes, subjective norms, PBC, and behavioral intentions in relation to following the set rules at youth shelters. Further, they distinguished between items assessing PBC (or perceived control) and those reflecting self-efficacy (or perceived difficulty). At the completion of each youth's stay at the shelter, shelter staff rated the rule adherence for that participant. Regression analyses revealed some support for the TPB in that subjective norm was a significant predictor of intentions. However, self-efficacy emerged as the strongest predictor of intentions and was the only significant predictor of rule-following behavior. Thus, the results of the present study indicate the possibility that self-efficacy is integral to predicting rule adherence within this context and reaffirm the importance of incorporating notions of people's perceived ease or difficulty in performing actions in models of attitude-behavior prediction.

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The study investigated theory of mind and central coherence abilities in adults with high-functioning autism (HFA) or Asperger syndrome (AS) using naturalistic tasks. Twenty adults with HTA/AS correctly answered significantly fewer theory of mind questions than 20 controls on a forced-choice response task. On a narrative task, there were no differences in the proportion of mental state words between the two groups, although the participants with HFA/AS were less inclined to provide explanations for characters' mental states. No between-group differences existed on the central coherence questions of the forced-choice response task, and the participants with HTA/AS included an equivalent proportion of explanations for non-mental state phenomena in their narratives as did controls. These results support the theory of mind deficit account of autism spectrum disorders, and suggest that difficulties in mental state attribution cannot be exclusively attributed to weak central coherence.