Examining Nonnormal Latent Variable Distributions for Non-Ignorable Missing Data

Missing not at random (MNAR) modeling for non-ignorable missing responses usually assumes that the latent variable distribution is a bivariate normal distribution. Such an assumption is rarely verified and often employed as a standard in practice. Recent studies for “complete” item responses (i.e., no missing data) have shown that ignoring the nonnormal distribution of a unidimensional latent variable, especially skewed or bimodal, can yield biased estimates and misleading conclusion. However, dealing with the bivariate nonnormal latent variable distribution with present MNAR data has not been looked into. This article proposes to extend unidimensional empirical histogram and Davidian curve methods to simultaneously deal with nonnormal latent variable distribution and MNAR data. A simulation study is carried out to demonstrate the consequence of ignoring bivariate nonnormal distribution on parameter estimates, followed by an empirical analysis of “don’t know” item responses. The results presented in this article show that examining the assumption of bivariate nonnormal latent variable distribution should be considered as a routine for MNAR data to minimize the impact of nonnormality on parameter estimates.     

Attention,spatial integration,and the tail of response time distributions in Stroop task performance

A few studies have examined selective attention in Stroop task performance through ex-Gaussian analyses of response time (RT) distributions. It has remained unclear whether the tail of the RT distribution in vocal responding reflects spatial integration of relevant and irrelevant attributes, as suggested by Spieler, Balota, and Faust (2000 Spieler, D. H., Balota, D. A. and Faust, M. E. 2000. Levels of selective attention revealed through analyses of reaction time distributions. Journal of Experimental Psychology: Human Perception and Performance, 26: 506–526. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). Here, two colour–word Stroop experiments with vocal responding are reported in which the spatial relation between colour and word was manipulated. Participants named colours (e.g., green; say “green”) while trying to ignore distractors that were incongruent or congruent words (e.g., red or green), or neutral series of Xs. The vocal RT was measured. Colour words in colour, white words superimposed onto colour rectangles (Experiment 1), and colour rectangles combined with auditory words (Experiment 2) yielded Stroop effects in both the leading edge and the tail of the RT distributions. These results indicate that spatial integration is not necessary for effects in the tail to occur in vocal responding. It is argued that the findings are compatible with an association of the tail effects with task conflict.     

From mental strain to burnout

This study examines the relationships between burnout and short-term consequences of mental strain within and outside human services professions, at the same time contributing to the understanding of the development of burnout as a long-term effect of impairing work and job design. A total of 294 German employees working in human services (N = 149) and industrial production (N = 145) completed the Oldenburg Burnout Inventory (OLBI) and four scales measuring short-term consequences of mental strain. Results of factor analyses confirmed that the elements of the OLBI's two-factor structure—exhaustion and disengagement—are distinct from a range of impairing short-term consequences of mental strain. In addition, structural equation modelling showed that each burnout dimension is differentially related to specific short-term consequences of strain: Exhaustion is primarily related to mental fatigue, whereas disengagement is primarily related to satiation and the experience of monotony. The findings did not differ substantially for the two occupational groups. Burnout, as a long-term consequence of impairing mental strain, is distinct from and presumably temporally-causally related to specific impairing short-term consequences of mental strain, which, in turn, can be attributed to inadequate job design.     

Light and movement: making contact with a traumatised and embattled latency girl

This paper shows a child psychotherapist learning and developing her technique as she attempts to make contact with a child who is extremely hard to reach. It is based on the first two years of three-times-weekly intensive psychotherapy of a latency girl who had little faith in a helpful therapeutic relationship. Her defences against such a relationship were entrenched and hard to shift. In this clinical work, the psychotherapist relies on close observation and her countertransference to develop a relationship with the child, in order to begin to make sense of her non-verbal emotional experience and communication.     

Bond modulus and stability of covalent solids

The chemical stabilities of molecules are determined by their LUMO–HOMO energy gaps. For solids, the analogues of these are their energy band gaps. However, solids are aggregates of molecules, so an energy alone cannot characterize their stabilities. An intensive parameter is needed. Such a parameter is the gap energy per molecular volume. The author has coined the name ‘bond modulus’ for this parameter because it tends to be proportional to elastic moduli and it has the same dimensions. It applies primarily to covalent solids with localized bonding. It is proportional to chemical hardnesses and bulk moduli, as well as octahedral shear moduli and inverse polarizabilities.     

外源性视觉选择性注意的时空特征

使用与目标出现位置无关的外周空现刺激作为线索,研究在不同刺激呈现间隔（ＳＯＡ）下它对不同偏心 视觉目标的辨别反应时的影响,以考察外源性觉选择性注意的加工特生,并下三种注意空间分布模型对选择性注意时空特征的不同预测,结果表明：１．外周突现刺激能够不随意地吸引注意,符合自动加工特性;２．注意转移以注意中心连续移动的方式进行,支持探照灯模型,不支持透镜模型和静态的空间梯度模型,并在注意移动速率进行了估计     

Characteristics and Effectiveness of an Intensive Military Outpatient Treatment Program for PTSD

This study describes the characteristics and global effectiveness of treatment of a military intensive outpatient treatment program for posttraumatic stress disorder (PTSD). Thirty-nine military personnel completed treatment outcome questionnaires. Results showed a statistically significant reduction in depression and PTSD symptoms after the participants completed 3 weeks of intensive outpatient therapy. The findings have clinical and research implications for the length, intensity, and focus of PTSD treatment.     

Designing and evaluating an intelligent augmented reality system for assisting older adults’ medication management

Intelligent Assistive Systems (IASs) provide personalised support to individuals to increase their autonomy and competence in performing activities. The personalisation of such technology represents a particular challenge, for the individuals abilities typically change over time. The aim of this research was to explore a theory-based, activity-centred framework for the development of IASs that both facilitate the active involvement of caregivers and target users and allow for adaptation to the individual over time.Medication management was focused on as a case study. Three older adults and two caregivers were involved in a co-design process of an IAS prototype system, the MED-AR, which uses projection-based augmented reality as the user interface technology. The theoretical framework for the design and evaluation of the MED-AR was activity theory. For the decision-making process of the MED-AR, formal argumentation theory was used. The major contributions of the study are (i) a formal framework for understanding the level of independence in activities and the way an IAS can tailor support to an individual and a situation, including caregivers; and (ii) a model for involving older adults and caregivers in a co-design process in the first phases of developing IASs.     

Aggregate temperament scores from multiple countries: Associations with aggregate personality traits,cultural dimensions,and allelic frequency

Aggregate temperament scores were calculated across 17 studies for 18 countries. These scores were analyzed in relation to aggregate personality scores, cultural orientation, and allelic distribution reported in prior studies. Cross-culture patterns were largely consistent with those previously reported for personality: countries high on Surgency (SUR) were high on Extraversion, high Negative Affectivity (NEG) was consistent with Neuroticism, and Regulatory Capacity (RC) with Agreeableness. Regarding cultural orientation, aggregate SUR was associated with low Power Distance and Long-Term Orientation; NEG with low Individualism and high Masculinity and Uncertainty Avoidance; and RC with low Power Distance and Masculinity. Higher proportion of MAOA-uVNTR low expression alleles was associated with low SUR and low RC; and A118G G-form allele proportion with low RC.