The Use of Propensity Scores in Mediation Analysis

Mediation analysis uses measures of hypothesized mediating variables to test theory for how a treatment achieves effects on outcomes and to improve subsequent treatments by identifying the most efficient treatment components. Most current mediation analysis methods rely on untested distributional and functional form assumptions for valid conclusions, especially regarding the relation between the mediator and outcome variables. Propensity score methods offer an alternative whereby the propensity score is used to compare individuals in the treatment and control groups who would have had the same value of the mediator had they been assigned to the same treatment condition. This article describes the use of propensity score weighting for mediation with a focus on explicating the underlying assumptions. Propensity scores have the potential to offer an alternative estimation procedure for mediation analysis with alternative assumptions from those of standard mediation analysis. The methods are illustrated investigating the mediational effects of an intervention to improve sense of mastery to reduce depression using data from the Job Search Intervention Study (JOBS II). We find significant treatment effects for those individuals who would have improved sense of mastery when in the treatment condition but no effects for those who would not have improved sense of mastery under treatment.     

Effects of training condition on the contribution of specific items to relational processing in baboons (Papio papio)

Relational processing involves learning about the relationship between or among stimuli, transcending the individual stimuli, so that abstract knowledge generalizable to novel situations is acquired. Relational processing has been studied in animals as well as in humans, but little attention has been paid to the contribution of specific items to relational thinking or to the factors that may affect that contribution. This study assessed the intertwined effects of item and relational processing in nonhuman primates. Using a procedure that entailed both expanding and contracting sets of pictorial items, we trained 13 baboons on a two-alternative forced-choice task, in which they had to distinguish horizontal from vertical relational patterns. In Experiment 1, monkeys engaged in item-based processing with a small training set size, and they progressively engaged in relation-based processing as training set size was increased. However, in Experiment 2, overtraining with a small stimulus set promoted the processing of item-based information. These findings underscore similarities in how humans and nonhuman primates process higher-order stimulus relations.     

Spirituality in Occupational Therapy: Do We Practice What We Teach?

This mixed-method study examined the responses of 97 occupational therapists on the subject of spirituality in occupational therapy practice. The inclusion of spirituality into the Occupational Therapy Practice Framework (2008) implies that clinicians address spirituality as a component of client-centered practice. This research revealed a gap between education, theory, and practice as evidenced in the quantitative and qualitative data. Although occupational therapy is intended to be holistic, therapists require a more complete understanding of what spirituality is and what the role of the occupational therapist is when addressing spirituality in evaluation or treatment. The discussion of this research provides information for future occupational therapy educators and educational programs as they seek to incorporate the construct of spirituality into curricula.     

Effect on Comprehension of Preposed versus Postposed Adverbial Phrases

A challenge for psycholinguistics is to describe how linguistic cues influence the construction of the mental representation resulting from the comprehension of a text. In this paper, we will focus on one of these linguistic devices: the sentence-initial positioning of spatial adverbials such as In the park.... Three self-paced reading experiments were conducted to test the ‘Discourse Framing Hypothesis’ according to which preposed adverbials can be seen as frame builders announcing that incoming contents satisfy the same informational criterion specified by the adverbial. Our results indicate that spatial adverbials do not play the same role when they are in sentence-initial and in sentence-final position. These results are discussed in the framework of Zwaan’s Event Indexing Model.     

Assessment of cognitive function across pregnancy using CANTAB: A longitudinal study

Significant changes in endogenous plasma hormone levels are required to sustain pregnancy which provides a unique opportunity to study their effect on cognitive function.     

Shyness and Psychosocial Functioning in South Korean Children

The purpose of this study was to examine whether anxious shyness and regulated shyness, initially identified in the Chinese culture, is found in South Korean children, and to explore whether these two forms of shyness were differentially related to children's psychosocial functioning. Participants were 544 fourth to sixth grade children (251 girls, M age = 11.38 years old) who were recruited from an elementary school in Bucheon City, South Korea. Children's anxious and regulated shyness were measured using peers' nominations and teachers' ratings, whereas their social preference and social impact were assessed using peers' nominations. Parents rated their children's temperamental shyness and effortful control, and children self‐reported their loneliness and interpersonal concerns. The results of confirmatory factor analysis replicated the two factor model of shyness found in previous studies of Chinese children. Anxious shyness and regulated shyness were positively associated and were similarly related to temperamental shyness. Anxious shyness was negatively related to effortful control and social preference, and positively associated with self‐reported loneliness and interpersonal concerns, whereas regulated shyness was positively related to effortful control and social preference and negatively associated with loneliness and social impact. These results were generally consistent with prior Chinese findings and provided preliminary support for the construct validity of anxious and regulated shyness in another Asian culture that emphasizes interdependence and modesty. Copyright © 2013 John Wiley & Sons, Ltd.     

Drop the Small Talk When Establishing Baseline Behaviour in Interviews

The present experiment investigated the behavioural patterns of interviewees when comparing their baseline behaviour, prior to the interview, with their behaviour during the investigative interview. Similar to what has been advised in the police literature, the truthful baseline behaviour was established prior to the interview through non‐threatening questions. The investigative part of the interview then followed in which the interviewee was aware that they would be assessed on whether they were lying. During the investigative part, interviewees either discussed the job that they had (truth tellers, n = 128) or pretended to have (liars, n = 115). Findings revealed that both liars and truth tellers' behavioural patterns differed between the baseline behaviour and the investigative part of the interview. The findings suggest small talk should not be used as a baseline comparison with the investigative part of the interview when determining if the interviewee is being deceitful. An alternative way of using a baseline lie detection method, the comparable truth method, is discussed. Copyright © 2014 John Wiley & Sons, Ltd.