On the confounds among retest gains and age-cohort differences in the estimation of within-person change in longitudinal studies: a simulation study

Although longitudinal designs are the only way in which age changes can be directly observed, a recurrent criticism involves to what extent retest effects may downwardly bias estimates of true age-related cognitive change. Considerable attention has been given to the problem of retest effects within mixed effects models that include separate parameters for longitudinal change over time (usually specified as a function of age) and for the impact of retest (specified as a function of number of exposures). Because time (i.e., intervals between assessment) and number of exposures are highly correlated (and are perfectly correlated in equal interval designs) in most longitudinal studies, the separation of effects of within-person change from effects of retest gains is only possible given certain assumptions (e.g., age convergence). To the extent that cross-sectional and longitudinal effects of age differ, obtained estimates of aging and retest may not be informative. The current simulation study investigated the recovery of within-person change (i.e., aging) and retest effects from repeated cognitive testing as a function of number of waves, age range at baseline, and size and direction of age-cohort differences on the intercept and age slope in age-based models of change. Significant bias and Type I error rates in the estimated effects of retest were observed when these convergence assumptions were not met. These simulation results suggest that retest effects may not be distinguishable from effects of aging-related change and age-cohort differences in typical long-term traditional longitudinal designs.     

Aging and visual masking: sensory and attentional factors

Visual tasks can yield quantitatively similar patterns of performance that reflect different underlying mechanisms in younger and older observers. In 3 experiments, we used the visual masking task of J. T. Enns and V. Di Lollo (1997) to examine 2 of these mechanisms: stimulus contrast and attention. Performance appeared to be equivalent for younger and older observers in some circumstances, although manipulation of contrast and attention suggested that older observers may use focal attention to enhance the perceptual clarity of the target. For older observers, impoverished visual representations may more readily be eliminated by manipulation of attention or by the presence of a mask, indicating that both attention and stimulus quality are important influences on performance.     

Developing mechanisms of temperamental effortful control

Studies of temperament from early childhood to adulthood have demonstrated inverse relationships between negative affectivity and effortful control. Effortful control is also positively related to the development of conscience and appears as a protective factor in the development of behavior disorders. In this study, the development of attentional mechanisms underlying effortful control was investigated in 2- to 3-year-old children, as indexed by their performance in a) making anticipatory eye movements to ambiguous locations and b) resolving conflict between location and identity in a spatial conflict task. The ability to make anticipatory eye movements to ambiguous locations within a sequence was clearly present at 24 months. By 30 months, children could also successfully perform a spatial conflict task that introduced conflict between identity and location, and at that age, children's success on ambiguous anticipatory eye movements was related to lower interference from conflict in the spatial conflict task. Children's performance on the eye-movement task was correlated with performance and reaction time on spatial tasks, and both were related to aspects of effortful control and negative affect as measured in children's parent-reported temperament.     

Visual marking: a convergence of goal- and stimulus-driven processes during visual search

Watson and Humphreys (1997) proposed that visual marking is a goal-directed process that enhances visual search through the inhibition of old objects. In addition to the standard marking case with targets at new locations, included in Experiment 1 was a set of trials with targets always at old locations, as well as a set of trials with targets varying between new and old locations. The participants' performance when detecting the target at old locations was equivalent to their performance in the full-baseline condition when they knew the target would be at old locations, and was worse when the target appeared at old locations on 50% of the trials. Marking was observed when the target appeared at new locations. In Experiment 2, an offset paradigm was used to eliminate the influence of the salient abrupt-onset feature of the new objects. No significant benefits were found for targets at new locations in the absence of onsets at new locations. The results suggest that visual marking may be an attentional selection mechanism that significantly benefits visual search when (1) the observer has an appropriate search goal, (2) the goal necessitates inhibition of old objects, and (3) the new objects include a salient perceptual feature.     

Sexual Intimacy,Mental Illness,and Homelessness

The current article reviews the literature on sexuality among individuals with a severe mental illness (SMI) who have experienced homelessness, a topic that has received little attention in the research literature, particularly from a community psychology perspective. The review begins with a synthesis of the literature on SMI and sexuality, followed by a review of the available literature on SMI, homelessness, and sexuality. It concludes with an interpretation of the findings using community psychology values and principles. The findings highlight the importance of intimate relationships to recovery for many individuals with an SMI who have experienced homelessness. Policy implications for homeless shelters and housing interventions are discussed.     

Families of Youth Who Have Sexually Offended: Understanding Shared Experiences and Moving Towards a Typology

Theoretical frameworks like Family Systems and Ecological Theories that postulate youth development is shaped by interconnected and interdependent systems begets further inquiry into classifications of such systems. Developing family typologies of youth who commit sexual crimes may inform etiology, service approaches, and judicial responses. In collaboration with a state Sex Offender Management Board, this study analyzed the perspectives of treatment providers (N = 19) on families of youth who have committed sexual crimes. Using deductive coding strategies including hypothesis and elaborative coding; observer triangulation and inter-subjective agreement; constant comparison analyses; and other rigorous qualitative techniques, findings confirmed and expanded upon extant literature. Results revealed a spectrum of open and closed family systems and common experiences including distorted perceptions of sexuality, protection of the family system, and other contextual influences. Findings are integrated with the theoretical frameworks and recommendations are offered to improve practices and typological research.     

Disgust predicts prejudice and discrimination toward individuals with obesity

This study examined the relevance of disgust to evaluations of an obese target person, and the connection between disgust and prejudice toward that person. Participants (n = 598) viewed an image of an obese or non‐obese woman, and then evaluated that woman on a number of dimensions (emotions, attitudes, stereotypes, desire for social distance). Compared with the non‐obese target, the obese target elicited more disgust, more negative attitudes and stereotypes, and a greater desire for social distance. Furthermore, disgust mediated the effect of the target's body size on all of the outcome variables (attitudes, stereotypes, social distance). Disgust plays an important role in prejudice and discrimination toward individuals with obesity, and might in part explain the pervasiveness of weight bias.     

Behavioral Outcomes of Parent-Child Interaction Therapy and Triple P—Positive Parenting Program: A Review and Meta-Analysis

We conducted a review and meta-analyses of 24 studies to evaluate and compare the outcomes of two widely disseminated parenting interventions—Parent-Child Interaction Therapy and Triple P-Positive Parenting Program. Participants in all studies were caregivers and 3- to 12-year-old children. In general, our analyses revealed positive effects of both interventions, but effects varied depending on intervention length, components, and source of outcome data. Both interventions reduced parent-reported child behavior and parenting problems. The effect sizes for PCIT were large when outcomes of child and parent behaviors were assessed with parent-report, with the exclusion of Abbreviated PCIT, which had moderate effect sizes. All forms of Triple P had moderate to large effects when outcomes were parent-reported child behaviors and parenting, with the exception of Media Triple P, which had small effects. PCIT and an enhanced version of Triple P were associated with improvements in observed child behaviors. These findings provide information about the relative efficacy of two programs that have received substantial funding in the USA and Australia, and findings should assist in making decisions about allocations of funding and dissemination of these parenting interventions in the future.

A note on using stratified alpha to estimate the composite reliability of a test composed of interrelated nonhomogeneous items

The relationship between stratified alpha (alpha(s)) and the reliability of a test composed of interrelated nonhomogeneous items is examined. It is mathematically demonstrated that when there is congeneric equivalence within the strata or subtests, the difference between the coefficients is a function of the variances of the loadings within the strata. When the items within each stratum are essentially tau equivalent, these variances are 0, and alpha(s) and true reliability are equal, provided errors of measurement are uncorrelated. If errors of measurement are positively correlated and there is essential tau equivalence within strata, stratified alpha will overestimate reliability. These findings indicate that recent studies involving stratified alpha (A. Kamata, A. Turhan, & E. Darandari, 2003; H. G. Osburn, 2000) need to be interpreted with some degree of caution. Nevertheless, the hypothetical population data presented in this article suggest that under certain circumstances, stratified alpha can be considerably greater than alpha and closer to the true reliability. Because the former is easily computed, it is recommended that with stratified tests, practicing researchers should routinely calculate both alpha and stratified alpha coefficients.     

Multilevel models for the experimental psychologist: Foundations and illustrative examples

Although common in the educational and developmental areas, multilevel models are not often utilized in the analysis of data from experimental designs. This article illustrates how multilevel models can be useful with two examples from experimental designs with repeated measurements not involving time. One example demonstrates how to properly examine independent variables for experimental stimuli or individuals that are categorical, continuous, or semicontinuous in the presence of missing data. The second example demonstrates how response times and error rates can be modeled simultaneously within a multivariate model in order to examine speed—accuracy trade-offs at the experimental-condition and individual levels, as well as to examine differences in the magnitude of effects across outcomes. SPSS and SAS syntax for the examples are available electronically.