Four simultaneous component models for the analysis of multivariate time series from more than one subject to model intraindividual and interindividual differences

A class of four simultaneous component models for the exploratory analysis of multivariate time series collected from more than one subject simultaneously is discussed. In each of the models, the multivariate time series of each subject is decomposed into a few series of component scores and a loading matrix. The component scores series reveal the latent data structure in the course of time. The interpretation of the components is based on the loading matrix. The simultaneous component models model not only intraindividual variability, but interindividual variability as well. The four models can be ordered hierarchically from weakly to severely constrained, thus allowing for big to small interindividual differences in the model. The use of the models is illustrated by an empirical example.This research has been made possible by funding from the Netherlands Organization of Scientific Research (NWO) to the first author. The authors are obliged to Tom A.B. Snijders, Jos M.F. ten Berge and three anonymous reviewers for comments on an earlier version of this paper, and to Kim Shifren for providing us with her data set, which was collected at Syracuse University.     

Sex differences and parallels in the development of externalizing behaviours in childhood: Boys’ and girls’ susceptibility to social preference among peers

This study examined whether being poorly preferred by peers may partially explain why boys with oppositional behaviour develop more conduct problems than girls. Children from the general Dutch population attending regular elementary schools (N = 759, 50.3% boys) were followed annually from age 7 to 10 years. Teachers-rated externalizing behaviour and peer-nominated social preference was assessed across four waves. Autoregressive cross-lagged models indicated that oppositionality predicted increases in conduct problems. Above and beyond this direct link, oppositionality predicted low social preference in subsequent years, which in turn predicted an increase in conduct problems. In this latter pathway, sex differences were found. That is, oppositional boys were as likely as oppositional girls to show an increase in low social preference one year later. However, boys who had low social preference scores showed stronger increases in conduct problems one year later, compared to girls who had low social preference scores. Hence, developmental models of externalizing behaviour should consider the possible sex-differential impact of troublesome peer-relationships to understand the development of milder to more severe externalizing behaviours.     

Cognitive Behavior Therapy for Fear of Cancer Recurrence: A Case Study

This case study describes the course and content of cognitive behavior therapy (CBT) for clinical fear of cancer recurrence (FCR) in a breast cancer survivor. The CBT for clinical FCR consisted of seven face-to-face therapy sessions and one telephone session. The primary treatment goal was to reduce FCR severity by modifying cognitive processes and dysfunctional behavior. Assessments of FCR and quality of life were completed by the breast cancer survivor pre-therapy, post-therapy, and at 6 and 12 months of post-therapy. In each treatment session, perceived control over FCR was assessed. A clinical nurse specialist participated in evaluation interviews. The patient’s perceived control over FCR increased during the therapy, and FCR severity declined to a non-clinical level. This improvement was still evident at the 6- and 12-month follow-up assessments and was supported by results for secondary and exploratory outcomes measures. FCR offers a great challenge for health care professionals due to the lack of effective treatment options. This case study shows how clinical FCR can be addressed with CBT and can contribute to the improvement of care for cancer survivors.     

Challenge me! Communicating in multicultural classrooms

The current study investigated the value of Socratic classroom communication (e.g., critical debate and challenging each other on content matters) among students from various cultures (clustered into Western Europeans, Eastern Europeans and Non-Europeans) and from members of faculty at an international university in Germany. Students from Western cultures where Socratic communication had been valued in the school systems reported a greater ease of engaging in the respective communication style than did Eastern European and Non-European students. Furthermore, we assessed how strongly the faculty valued the respective kinds of behavior. The results show that overall students underestimated the extent to which Socratic communication behavior was esteemed by members of faculty. In addition, faculty members perceived themselves to be more explicit about their pedagogical principles than they were perceived by students. Finally, the easier it was for students to show Socratic classroom communication, the more academically satisfied they were and the better their grades. The results are discussed with regard to practical implications and the internationalization of universities.     

Subspace K-means clustering

To achieve an insightful clustering of multivariate data, we propose subspace K-means. Its central idea is to model the centroids and cluster residuals in reduced spaces, which allows for dealing with a wide range of cluster types and yields rich interpretations of the clusters. We review the existing related clustering methods, including deterministic, stochastic, and unsupervised learning approaches. To evaluate subspace K-means, we performed a comparative simulation study, in which we manipulated the overlap of subspaces, the between-cluster variance, and the error variance. The study shows that the subspace K-means algorithm is sensitive to local minima but that the problem can be reasonably dealt with by using partitions of various cluster procedures as a starting point for the algorithm. Subspace K-means performs very well in recovering the true clustering across all conditions considered and appears to be superior to its competitor methods: K-means, reduced K-means, factorial K-means, mixtures of factor analyzers (MFA), and MCLUST. The best competitor method, MFA, showed a performance similar to that of subspace K-means in easy conditions but deteriorated in more difficult ones. Using data from a study on parental behavior, we show that subspace K-means analysis provides a rich insight into the cluster characteristics, in terms of both the relative positions of the clusters (via the centroids) and the shape of the clusters (via the within-cluster residuals).     

The role of the magnocellular and parvocellular pathways in the attentional blink

The attentional blink refers to the transient impairment in perceiving the 2nd of two targets presented in close temporal proximity in a rapid serial visual presentation (RSVP) stream. The purpose of this study was to examine the effect on human attentional-blink performance of disrupting the function of the magnocellular pathway--a major visual-processing pathway specialized in temporal segregation. The study was motivated by recent theories that relate the attentional blink to the limited temporal resolution of attentional responses, and by a number of poorly understood empirical findings, including the effects on the attentional blink of luminance adaptation and distraction. The attentional blink was assessed for stimuli on a red background (Experiment 1), stimuli on an equiluminant background (Experiment 2), and following flicker or motion adaptation (Experiment 3), three psychophysical manipulations known to disrupt magnocellular function. Contrary to our expectations, the attentional blink was not affected by these manipulations, suggesting no specific relationship between the attentional blink and magnocellular and/or parvocellular processing.