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451.
Bayesian inference for graphical factor analysis models   总被引:1,自引:0,他引:1  
We generalize factor analysis models by allowing the concentration matrix of the residuals to have nonzero off-diagonal elements. The resulting model is named graphical factor analysis model. Allowing a structure of associations gives information about the correlation left unexplained by the unobserved variables, which can be used both in the confirmatory and exploratory context. We first present a sufficient condition for global identifiability of this class of models with a generic number of factors, thereby extending the results in Stanghellini (1997) and Vicard (2000). We then consider the issue of model comparison and show that fast local computations are possible for this purpose, if the conditional independence graphs on the residuals are restricted to be decomposable and a Bayesian approach is adopted. To achieve this aim, we propose a new reversible jump MCMC method to approximate the posterior probabilities of the considered models. We then study the evolution of political democracy in 75 developing countries based on eight measures of democracy in two different years. We acknowledge support from M.U.R.S.T. of Italy and from the European Science Foundation H.S.S.S. Network. We are grateful to the referees and the Editor for many useful suggestions and comments which led to a substantial improvement of the paper. We also thank Nanny Wermuth for stimulating discussions and Kenneth A. Bollen for kindly providing us with the data-set.  相似文献   
452.
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454.
Attentional biases for negative interpersonal stimuli in clinical depression   总被引:14,自引:0,他引:14  
An information-processing paradigm was used to examine attentional biases in clinically depressed participants, participants with generalized anxiety disorder (GAD), and nonpsychiatric control participants for faces expressing sadness, anger, and happiness. Faces were presented for 1000 ms, at which point depressed participants had directed their attention selectively to depression-relevant (i.e., sad) faces. This attentional bias was specific to the emotion of sadness; the depressed participants did not exhibit attentional biases to the angry or happy faces. This bias was also specific to depression; at 1000 ms, participants with GAD were not attending selectively to sad, happy, or anxiety-relevant (i.e., angry) faces. Implications of these findings for both the cognitive and the interpersonal functioning of depressed individuals are discussed and directions for future research are advanced.  相似文献   
455.
English-speaking children typically avoid using regular plurals in novel grammatical deverbal compounds as in rat eater but allow irregular plurals as in mice eater (Gordon, 19985). To explain these data, it has been argued that level-ordering model constrains the production of morphologically complex words, including those with which children have had little to no experience. If level-ordering can be supported, children should avoid regular plurals in their ungrammatical deverbal compounds like a breaker-bottle. Seventy-two English-speaking children were included in the present study, 36 from Britain and 36 from Canada. The results showed that 50% of the children who produced ungrammatical compounds included regular plurals in the compounds they produced. Conversely, none of the children who produced grammatical compounds included regular plurals. These results indicate that level-ordering does not constrain children's production of ungrammatical compounds. These results raise the possibility that level-ordering may not be a valid constraint of children's compounding in general.  相似文献   
456.
ABSTRACT— Research has shown that experience acquired in infancy dramatically affects face-discrimination abilities. Yet much less is known about whether face processing retains any flexibility after the 1st year of life. Here, we show that early experience with an individual infant face can modulate the recognition performance of 3-year-old children and the perceptual processes they use to recognize infant faces ( Experiment 1 ). Similar experience acquired in adulthood does not produce measurable effects ( Experiment 2 ). We also show that the effects of early-acquired experience with an infant face become dormant during development in the absence of continued experience ( Experiment 3 ) and can be reactivated in adulthood by reexposure to the original experience ( Experiment 2 ). Overall, the results indicate that early experience can preserve the face-processing system from the loss of plasticity that would otherwise take place between childhood and adulthood.  相似文献   
457.
In this fMRI-study, 6-year-old children considered at risk for dyslexia were compared with an age-/gender-matched control group for differences in brain activation when presented with visual stimuli differing in demands for literacy processing. Stimuli were nameable pictures, brand logos familiar to children, and written words - these were either regularly spelled using early-acquired rules ("alphabetic") or more complex ("orthographic"). Brain responses distinguished between the presentation conditions, as a function of group, within many cortical areas. Activation in the alphabetic and orthographic conditions in the left angular gyrus correlated with individual at-risk index scores, and activation in inferior occipito-temporal regions further indicated differential activation for the two groups related to orthographic processing, especially. Since similar patterns are reported in adult dyslexics when processing written words, it appears that sensitivity to the cortical differentiation of reading networks is established prior to formal literacy training.  相似文献   
458.
This study evaluated categories of attachment style and the maternal attitude toward educational role in a sample of 30 mothers of obese children and a control group of 80 mothers of children of normal weight. All mothers completed the 1994 Attachment Style Questionnaire and the 1958 Parental Attitude Research Instrument. 30 mothers (M age 37.4 yr., range 31 to 54 years; M yr. of education 11.6, range 5 to 18 years) of obese children (range 30 to 60% above normal weight) and a control group of 80 mothers (M age 37.1 yr., range 29 to 52 years; M yr. of schooling 11.4, range 5 to 18 years) of children with normal weight were contacted at the primary school attended by their children and joined the project voluntarily. Age and number of years of education were not significantly different between the two groups of women. There was a significant prevalence of the Insecure Attachment Style in the group of mothers with obese children (66.6%) as compared to the control group of mothers of children of normal weight (38.5%) and significantly higher scores on 6 subscales of the Parental Attitude Research Instrument of Obese compared to Nonobese children. These data indicate that obese children's mothers tend to make the family their exclusive centre of interest. They also tend to dedicate themselves to their children with possessiveness and hyperprotection. They seem to have an insistent requirement of idealisation of their own role as parent and reward expectations that confirm the efficiency of the care they provide their children. Consequently, these findings suggest that in addition to dietetic treatment, it may be important to include a psychological intervention, which involves the mother and aims to modify the relational dynamics between the mother and her obese child.  相似文献   
459.
Personality disorders (PD) are a prevalent class of mental disorders that interfere with functioning and cause subjective distress while increasing the intensity and duration of Axis I clinical syndromes, and therefore assessing PD is important even when PDs are not the focus of treatment. The purpose of these studies was to develop and test a new Spanish version of a self-report measure of PD, the Wisconsin Personality Inventory-IV (WISPI-IV) that would be psychometrically equivalent to the English version while also maintaining the same interpersonal content, which is based on Benjamin's analysis of the PD criteria using her Structural Analysis of Social Behavior (SASB) model (1974). Study 1 participants completed the WISPI-IV twice over a two-week interval. For Study 2, participants from two sites in Spain and one site in Argentina completed Spanish versions of the WISPI-IV and other personality measures. SASB-analysis of the translated items showed high correspondence between the interpersonal content of the English version and the Spanish version demonstrating theoretical validation in relation to other PD measures. The Spanish WISPI-IV showed satisfactory reliability based on test-retest correlations and alphas for internal consistency. Study 2 showed the Spanish WISPI-IV had good convergent validity with the Spanish versions of the IIP and SCID-II and performed similarly to the English versions of these measures. Our goal in translating the WISPI-IV was to extend this measure to Spanish-speakers in language that would be understood by different Hispanic sub-groups, however research team members and subjects had a variety of suggestions for changes in item wording. This reflects the difficulty with creating a "neutral" Spanish version of any assessment given regional differences.  相似文献   
460.
We present a brief scale derived from the Nicotine Dependence Syndrome Scale (NDSS). We used a sample of 1.061 daily smokers, which was obtained from five Primary Care Health Centers, a Unit of Alcoholism, and a Smoking Cessation Unit. All smokers were evaluated with the NDSS and the SCID to assess nicotine dependence according to DSM-IV criteria. The results indicate the existence of a general factor of nicotine dependence according to the NDSS. We selected the items with a higher factor loading (>.50), obtaining a short scale of 6 items. With this brief scale, we obtained results similar to those of the total scale in the diverse variables (sociodemographic and smoking) of the study. Scale reliability is satisfactory (a= .79), the correlation between the short and the total scale is very high (r=.95, p<.001) and the short scale discriminates the smokers in terms of cigarette consumption and nicotine dependence, as assessed with the SCID. The operation under the ROC curve is excellent (area under the curve .84). The data indicate the usefulness of this brief scale (NDSS-S) to assess nicotine dependence in smokers.  相似文献   
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