A molecular dynamics study of atom mobility on steps of a Si(100) surface

Thermally activated motions of atoms on steps of a Si(100) surface have been studied using molecular dynamics simulations with standard three-body potentials. In the temperature interval 100-450K, these motions have two salient characteristics: firstly, a growth rate t^m leading to displacements of 1A in some tens of picoseconds and secondly, a marked dependence on the step morphology. These results are discussed in the light of experimental observations of step dynamics.     

Roughening kinetics of reactively sputter-deposited Ti-Al-N films on Si(100)

The roughening kinetics of Ti_{1? x} Al _x N (0?x? 1) films 600 nm thick synthesized by reactive dc magnetron sputtering on Si(100) substrates has been investigated by atomic force microscopy (AFM). The quantification of surface roughening was achieved by calculation of both vertical root-mean-square roughness and lateral correlation lengths of the film surface using the height-height correction functions of measured AFM images. For all the Ti_{1? x} Al _x N films, a steady roughness exponent α = 0.94 ± 0.03 was determined. The evolution of the surface topography as a function of Al concentration is discussed in terms of the competition between surface diffusion and shadowing instability during sputter deposition.     

Deployment of spatial attention to a structural framework: exogenous (alerting) and endogenous (goal-directed) factors

The main question examined in the present work was whether spatial attention can be deployed to an appropriate structural framework not only endogenously when the framework is displayed continuously, as in previous work, but also exogenously, when it is displayed transiently 100 ms before the target. The results of five experiments answered that question in the negative. We found that the onset transient triggered by a brief presentation of the structural framework did enhance the response to the upcoming target. That enhancement, however, was due not to the framework itself but to the alerting effect produced by its sudden onset, witness the finding that the same enhancement was produced by an onset transient triggered by a featureless stimulus (i.e., by a brief dimming of the entire screen, in the absence of a structural framework). We conclude that spatial attention can be deployed to the region demarcated by a structural framework when it is deployed endogenously but not when it is deployed exogenously. A theoretical account of the results is proposed in terms of the temporal dynamics of the locus c?ruleus/norepinephrine neuromodulatory system.     

Ab-initio study of the structural,electronic, elastic and vibrational properties of HfX (X = Rh,Ru and Tc)

The structural, elastic, electronic and phonon properties of HfX (X = Rh, Ru and Tc) in the caesium-chloride phase have been investigated using the density functional theory within the generalized gradient approximation. The optimized lattice constant (a₀), bulk modulus (B) and the elastic constants (C_ij) are evaluated. The results are in a good agreement with the available experimental and theoretical data in the literature. Electronic band structures and densities of states have been derived for these compounds. The present band structure calculations indicate that the phases of caesium-chloride HfX (X = Rh, Ru and Tc) compounds are metals. Phonon dispersion curves and their corresponding total and projected density of states have been obtained using the direct method. The phonon spectra suggest that these compounds are dynamically stable in the caesium-chloride phase.     

Discriminating preexperimental (semantic) from learned (episodic) associations: A speed-accuracy study

This research investigates the process by which people discriminate preexperimental (semantic) from experimental (episodic) associations. Subjects were instructed to recognize (reply old) only to experimentally studied materials. The questions are how is context information used to select relevant memories, and how successful is the exclusion of irrelevant information? The recognition accuracy and the retrieval speed (rate of approach to asymptotic accuracy) are jointly measured using a speed-accuracy trade-off (SAT) paradigm, with collateral reaction time (RT) experiments. Experiment 1 presented both semantically related and unrelated pairs for study. In Experiment 3, semantically related pairs were never presented for study and preexperimentally related lures could be rejected by rule. Semantically related lures in both of these SAT experiments showed evidence for elevated false alarm rates early in retrieval, followed by late suppression of false alarms (at about 1 s). When related pairs were studied in the experiment, suppression was incomplete; when related pairs were never studied, rule-based supersuppression obtained. Results from collateral reaction time studies (Experiments 2 and 4) showed points that corresponded to the pattern of results in Experiments 1 and 3 near asymptote, although the RT data by themselves would have been interpreted quite differently. These results are compatible with a single-store, two-phase retrieval model in which context information, or recall-like information about correct pair mates, is used to correct spurious false alarms resulting from the incomplete filtering of semantic information.     

A parametric study of volume and surface judgments

Ten prisms and 10 plates differing in height were presented to 30 male and 30 female college students whose task was to judge volume and surface of the solids. No sex differences in volume or surface estimates were found. Increasing the height of a prism from a cube initially resulted in underestimates of volume; for prisms whose heights deviated markedly from a cube, a consistent and steadily increasing tendency to overestimate volume occurred. Decreasing the height of a plate from a cube initially had no significant effect on surface estimates, but with a marked decrease in height, a consistent and steadily increasing tendency to underestimate surface resulted.     

Complainer Profile Identification (CPI): properties of a new questionnaire on subjective cognitive complaints

Subjective cognitive complaints (SCC) and their role as a possible indicator for subsequent dementia became of growing interest in recent research. In contrast to studies that focused primarily on memory complaints, we aimed to (a) evaluate a questionnaire to register SCC in multiple cognitive domains (Complainer Profile Identification, CPI), (b) assess the association between SCC and psychosocial variables, and (c) assess whether complainer types can be differentiated. Confirmatory factor analysis to evaluate construct validity was computed based on a sample of 734 healthy participants (mean [M] = 43.15 years). On a subsample of 644 participants, the relationship between the total level of SCC with age, depression, social integration, and aging stereotypes was assessed utilizing multiple regression analysis. Differences in complainer types were assessed by multivariate analysis of variance. The results indicate sound psychometric properties of the CPI. The overall level of SCC is largely influenced by depressiveness, whereas executive complainers show the highest level of depressive affect, being overall younger and less socially integrated.     

The differential aptitude test (language usage and spelling): A clinical study of a computerized form

As part of the Leicester/DHSS project on microcomputer-aided assessment, 103 subjects were tested and retested on standard and computerized versions of the Differential Aptitude Tests for Language Usage and Spelling (Forms S and T). Subjects were generally faster on the computerized versions than on the standard versions. On the Language Usage test, subjects scored significantly higher on the computerized than on the standard test. The correlations found between the standard and computerized versions were modest in comparison to the original test-retest reliabilities. It is concluded that these data argue against the claim that the current computerized versions of the tests are psychometrically parallel to the standard versions. This research, which was carried out when the authors were at the Department of Psychology, University of Leicester, was supported by the United Kingdom Department of Health and Social Security.     

A validation study of a transferred group intelligence test(1)

The purpose of the research was to conduct a validation study of a transferred group intelligence test. The Lorge-Thorndike Intelligence Test, Level A, Form 1 was translated to Hebrew and administered to an Israeli sample comparable to the original norming group. The results obtained were concerned with variability, reliability, validity, item analysis, intercorrelations among subtests, and factor analysis. While few comparisons of the Israeli sample with the original data were made, the validation of the transferred test was examined in the light of other criteria for evaluating a new test. The suitability of the transferred test for Israeli high achievers from high-status families was supported by the results. The major conclusions were: (1) the total mean IQ scores of Israeli students were approximately the same as the American mean; (2) mean raw scores increased with age; (3) relative difficulty of individual items remained stable through translation and administration in Israeli culture, in three out of five subtests; (4) it appears reasonable to suggest that the factor structure of the translated test is consistent with the intent of the original.     

Validation and study of psychometric properties of a French version of the Highly Sensitive Person Scale (HSPS-FR)

IntroductionThe Highly Sensitive Person Scale based on the sensory-processing sensitivity is a self-assessment questionnaire consisting of 27 items. The scale is designed in order to identify individuals with high sensitivity.ObjectiveThe objective was to develop a French version of the scale. We tested its internal consistency and test-retest reliability on a French population sample. Another aim of this study was also to question the multidimensionality of the scale, for which several different models are suggested within the literature.MethodAfter translation and back-translation, a validation study was conducted on 814 adults. They were invited to complete an online questionnaire during the lockdown implemented due to COVID 19, between March 31st and May 11th (2020).ResultsThe internal reliability of the French version of HSPS was very good, with a Cronbach's alpha of .90, as was that of the factors. Correlations between factors were significant (p < .001). The intra-class correlation (ICC) for test-retest was .889 (0.874–0.903; 95% confidence interval). Factor analyses suggested a 4-factors structure, mixing the models found in the literature.ConclusionsThis study focused on a French adaptation of the HSPS scale. The results showed good psychometric qualities and stayed true to the original HSPS scale. The scale could be useful both to practitioners in their clinical practice and to researchers in fundamental research.     

Reducing problem behaviors in a residential unit using structural analysis and staff management procedures: A preliminary study

A structural analysis of the problem behaviors of 32 adults with mental retardation living together in a residential facility showed that a disproportionate number of these behaviors were associated with a period of time scheduled for leisure activities. A staff management program was implemented during this time which included activity and staff scheduling, staff inservice training, and staff performance monitoring and feedback. The results showed an 83% decrease in problem behaviors when the program was implemented during the leisure period and no decrease in problem behaviors during adjacent time periods where the program was not utilized. Follow-up assessments indicated maintenance of these decreased levels of behavior at 3 and 6 months. It was concluded that this approach of combining a structural analysis with staff management procedures was effective in reducing a high level of problem behavior in a residential setting. The results are discussed with regard to pragmatic strategies for the pretreatment analysis of problem behaviors in residential settings, and the role of organizational behavior management techniques in habilitative programing for individuals with behavior disorders.     

Premature conclusions about the signal-to-noise ratio in structural equation modeling research: A commentary on Yuan and Fang (2023)

In a recent article published in this journal, Yuan and Fang (British Journal of Mathematical and Statistical Psychology, 2023) suggest comparing structural equation modeling (SEM), also known as covariance-based SEM (CB-SEM), estimated by normal-distribution-based maximum likelihood (NML), to regression analysis with (weighted) composites estimated by least squares (LS) in terms of their signal-to-noise ratio (SNR). They summarize their findings in the statement that “[c]ontrary to the common belief that CB-SEM is the preferred method for the analysis of observational data, this article shows that regression analysis via weighted composites yields parameter estimates with much smaller standard errors, and thus corresponds to greater values of the [SNR].” In our commentary, we show that Yuan and Fang have made several incorrect assumptions and claims. Consequently, we recommend that empirical researchers not base their methodological choice regarding CB-SEM and regression analysis with composites on the findings of Yuan and Fang as these findings are premature and require further research.     

The dual path of the rejection (dis)identification model: A study on adolescents with a migrant background

Ethnic-based rejection, especially when prolonged over time, can result in withdrawal (e.g., resignation) and antisocial (e.g., delinquent) behaviors. Rejection (dis)identification literature suggests that identification with the minority (ethnic) group and disidentification with the majority (national) group mediate the relationship between rejection and different dimensions of well-being. Through secondary analyses of survey data from an international sample of adolescents with a migrant background (N = 1,163) we tested the predictions that, following chronic experiences of rejection, disidentification from the national (rejecting) group will increase withdrawal and feelings of resignation whereas identification with the ethic (rejected) group will have a protective role toward delinquent behaviors. Results of the path analysis were consistent with these hypotheses without significant differences between immigrant generations. The study sheds light on the multifaceted nature of identification processes following social rejection and contributes to the integration of the rejection-identification model with classical theorizations of social exclusion.     

Emotional valence,sense of agency and responsibility: A study using intentional binding

We investigated how the emotional valence of an action outcome influences the experience of control, in an intentional binding experiment. Voluntary actions were followed by emotionally positive or negative human vocalisations, or by neutral tones. We used mental chronometry to measure a retrospective component of sense of agency (SoA), triggered by the occurrence of the action outcome, and a prospective component, driven by the expectation that the outcome will occur. Positive outcomes enhanced the retrospective component of SoA, but only when both occurrence and the valence of the outcome were unexpected. When the valence of outcomes was blocked – and therefore predictable – we found a prospective component of SoA when neutral tones were expected but did not actually occur. This prospective binding was absent, and reversed, for positive and negative expected outcomes. Emotional expectation counteracts the prospective component of SoA, suggesting a distancing effect.     

Objects and properties: A study of the breakdown of semantic memory

Abstract

This paper reports a study of the breakdown of semantic memory in the case of a subject with semantic dementia. The first experiment shows that the subject failed to comprehend words of low familiarity and word frequency, even though the spoken word forms were recognised as familiar. Experiments 2 and 3 showed (a) that the recall of word meanings in definition tasks did not vary with the generality of the word meaning (e.g. category, basic level, or subordinate property) but varied instead with the concept familiarity and frequency of the name; (b) that the ability to verify properties of basic-level objects was not affected by the ability to comprehend the property name, but depended instead on the degree of knowledge demonstrated for the object name in definition tasks; (c) that properties were frequently verified correctly when the object had been defined only to the superordinate level. It is argued that the results do not support the widely held view that, in general, specific information is lost first when semantic memory breaks down. The selective failure to recall specific information for some word meanings is discussed with reference to two theoretical accounts.