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971.
Mixture analysis is commonly used for clustering objects on the basis of multivariate data. When the data contain a large number of variables, regular mixture analysis may become problematic, because a large number of parameters need to be estimated for each cluster. To tackle this problem, the mixtures-of-factor-analyzers (MFA) model was proposed, which combines clustering with exploratory factor analysis. MFA model selection is rather intricate, as both the number of clusters and the number of underlying factors have to be determined. To this end, the Akaike (AIC) and Bayesian (BIC) information criteria are often used. AIC and BIC try to identify a model that optimally balances model fit and model complexity. In this article, the CHull (Ceulemans & Kiers, 2006) method, which also balances model fit and complexity, is presented as an interesting alternative model selection strategy for MFA. In an extensive simulation study, the performances of AIC, BIC, and CHull were compared. AIC performs poorly and systematically selects overly complex models, whereas BIC performs slightly better than CHull when considering the best model only. However, when taking model selection uncertainty into account by looking at the first three models retained, CHull outperforms BIC. This especially holds in more complex, and thus more realistic, situations (e.g., more clusters, factors, noise in the data, and overlap among clusters).  相似文献   
972.
973.
Insufficient sleep, as well as the incidence of anxiety disorders, both peak during adolescence. While both conditions present perturbations in fear-processing-related neurocircuitry, it is unknown whether these neurofunctional alterations directly link anxiety and compromised sleep in adolescents. Fourteen anxious adolescents (AAs) and 19 healthy adolescents (HAs) were compared on a measure of sleep amount and neural responses to negatively valenced faces during fMRI. Group differences in neural response to negative faces emerged in the dorsal anterior cingulate cortex (dACC) and the hippocampus. In both regions, correlation of sleep amount with BOLD activation was positive in AAs, but negative in HAs. Follow-up psychophysiological interaction (PPI) analyses indicated positive connectivity between dACC and dorsomedial prefrontal cortex, and between hippocampus and insula. This connectivity was correlated negatively with sleep amount in AAs, but positively in HAs. In conclusion, the presence of clinical anxiety modulated the effects of sleep-amount on neural reactivity to negative faces differently among this group of adolescents, which may contribute to different clinical significance and outcomes of sleep disturbances in healthy adolescents and patients with anxiety disorders.  相似文献   
974.
As standardized measures of cognitive abilities and academic achievement continue to evolve, so do the relations between the constructs represented in these measures. A large, nationally representative sample of school‐aged children and youth between 6 and 19 years of age (N = 4,194) was used to systematically evaluate the relations between cognitive abilities and components of academic achievement in mathematics. The cognitive abilities of interest were those identified from the Cattell–Horn–Carroll model of intelligence. Specific areas of mathematics achievement included math calculation skills and math problem solving. Results suggest that fluid reasoning (Gf), comprehension‐knowledge (Gc), and processing speed (Gs) have the strongest and most consistent relations with mathematics achievement throughout the school years.Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   
975.
Despite the emphasis on threat appraisal in cognitive models of anxiety, self-report measures of related processes in children and adolescents have been lacking. This paper reports on the development and preliminary psychometric evaluation of a new measure of threat appraisal for children and adolescents – the Threat Appraisal Questionnaire for Children (TAQ-C). Based on current conceptualisations of threat appraisal, the TAQ-C was designed to index the construct across three dimensions: probability, cost, and coping difficulties. Confirmatory Factor Analysis was used to examine this structure in a community sample of n = 312 children (ages 9–15 years, 55% female). Results indicated that the scores on the instrument capture three factors (Probability, Cost and Coping difficulties). Moreover, a model in which the 1st-order factors loaded significantly on a single 2nd order factor of threat in general, was supported. The TAQ-C was found to demonstrate good internal consistency, and acceptable levels of test-retest reliability within a 3–4 week interval, when evaluated with a subsample of n = 51 children. Support for convergent validity was demonstrated, with TAQ-C scores found to correlate strongly with existing measures of child anxiety, and conceptually related cognitive processes. Divergent validity was also evidenced, with low correlations found between TAQ-C scores and the unrelated construct measure of Hyperactivity-Inattention. The TAQ-C, therefore, appears to be a promising measure with a range of potential applications for child and adolescent settings.  相似文献   
976.
High prevalence rates of aggression during adolescence and associated adjustment difficulties for perpetrators and victims highlight the need for effective violence prevention programs. School-based prevention programs are advantageous as they occur in a key setting for youths' social and emotional development. The current study compared the efficacy of a combined universal violence prevention approach that included individual-level skill-building (i.e., lessons from Second Step) and school environment (i.e., Olweus Bullying Prevention Program; OBPP) interventions to OBPP alone. Participants were 231 sixth, seventh, and eighth graders (ages 11–15; M?=?12.6, SD?=?1.0) in middle school (48?% male, 67?% African American). A total of 14 classrooms were randomly assigned to the combined intervention (seven) or OBPP only comparison (seven) condition, split evenly across grades. Intervention effects were moderated by disability status and gender. Among students without disabilities those who received the combined intervention reported greater increases in anger regulation coping skills than those in the comparison condition. In contrast, among youth with disabilities greater increases in teacher-rated social skills were found for students in the combined intervention than students in the comparison condition at posttest. Gender-moderated effects included greater decreases in teacher ratings of externalizing problems and bullying behaviors for boys in the combined intervention versus the comparison condition at posttest. Study results inform school-based violence prevention programs and are discussed along with implications.  相似文献   
977.
978.
We conducted four Stroop color–word experiments to examine how multiple stimuli influence interference. Experiments 1a and 1b showed that interference was strong when the word and color were integrated, and that visual and auditory words made independent contributions to interference when these words had different meanings. Experiments 2 and 3 confirmed this pattern when the word information and color information were not integrated, and hence when overall interference was substantially less. Auditory and visual interference effects are comparable except when the visual distracter is integrated with the color, in which case interference is substantially enhanced. Overall, these results are interpreted as being most consistent with a joint influence account of interference as opposed to a capture account.  相似文献   
979.
The author discusses the traditional interpretations of the principal dramatis personae in Verdi's Rigoletto, suggesting that the opera expresses the composer's unconscious but highly perceptive and intuitive exploration of: (i) paranoid and perverse father-daughter oedipal dynamics as enacted between Rigoletto and Gilda; (ii) a folie-à-deux sado-masochistic relationship between Rigoletto and the Duke; (iii) the avoidance of conscious guilt and responsibility for Rigoletto's part in the tragedy through the rejection of insight achieved via massive projection, an addiction to mania, and perversion. In this respect Rigoletto is compared with King Lear. Some technical aspects of Verdi's compositional style employed to portray the contrasting characters of the protagonists are analysed. The paper also touches on Verdi's own possible unconscious (as well as conscious) investment in this particular opera, noting similarities between Verdi's portrait of the tragic, hunchback jester and his own self-depiction. The author notes similarities and contrasts between his analysis of the opera and recent papers by Hudson (1992),Tarnopolsky (1995)and Bergstein (2003)on the same subject.  相似文献   
980.
Five studies show that gift recipients are more appreciative of gifts they explicitly request than those they do not. In contrast, gift givers assume that both solicited and unsolicited gifts will be equally appreciated. At the root of this dilemma is a difference of opinion about what purchasing an unsolicited gift signals: gift givers expect unsolicited gifts will be considered more thoughtful and considerate by their intended recipients than is actually the case (,  and ). In our final two studies, we highlight two boundary conditions for this effect: identifying a specific gift and using money as a gift. When gift recipients request one specific gift, rather than providing a list of possible gifts, givers become more willing to purchase the requested gift (Study 4). Further, although givers believe that recipients do not appreciate receiving money as much as receiving a solicited gift, recipients feel the opposite about these two gift options (Study 5).  相似文献   
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