First record: a methodological approach to counter sampling bias

One goal of survey research is to optimize sampling procedures so that the collected data will produce accurate population estimates. In this context, sampling bias is a primary threat to a study's validity. If individuals who do not respond are a random sample of the population, then the estimates obtained from such a subsample are unbiased. However, as the percentage of nonrespondents increases, the assumption of unbiased estimation becomes increasingly tenuous. At this point an investigator has two choices: delete all subjects who have not provided data as part of the first data collection, or allow a respondent's point of entry to define his baseline measures for the study. No previous discussion of the latter option has been noted in the methods literature. Therefore the authors have termed this approach to baseline the "first record". Conditions under which the "first record" technique would be appropriate or inappropriate are discussed.     

Help when it's needed first: a controlled evaluation of brief, preventive behavioral family intervention in a primary care setting

This study evaluated the effects of a brief 3- to 4-session behavioral family intervention program for parents of preschool-aged children in a primary care setting, compared to parents in a wait-list control condition. Parents receiving the Primary Care Triple P-Positive Parenting Program intervention reported significantly lower levels of targeted child behavior problems, dysfunctional parenting, and reduced parental anxiety and stress in comparison to wait-listed parents at postassessment. These short-term effects were largely maintained at 6-month follow-up assessment of the intervention group. Implications of these findings for the prevention of behavioral and emotional problems in children are discussed.     

Bimanual curvature discrimination of hand-sized surfaces placed at different positions

This study explores bimanual curvature discrimination of cylindrically curved, hand-sized surfaces. The setup was designed so that the postures of the observers' left and right arms and hands were thesame as if the observers were holding a large object in their hands. We measured psychometric curves for observers who used active, dynamic touch; these curvatures ranged from 1.18 to 4.05/m. Bimanual discrimination thresholds were found to be between 0.26 and 0.38/m on average; they were in the same range as unimanual thresholds reported in previous studies. Variation of (1) the horizontal distance between the stimuli or (2) the position of the setup had no effect on thresholds. In addition, we found that a number of observers showed discrimination biases in which they judged two physically different curvatures to be equal. Biases were of the same order of magnitude as the thresholds and could be either positive or negative. These biases can possibly be explained by small differences in left and right arm movements, an explanation that is supported by the position dependence of biases for individual observers.     

Academic performance,popularity, and depression predict adolescent substance use

Eighty-nine high school seniors completed a questionnaire on their feelings and activities, including their use of drugs. Adolescents with a low grade point average, high popularity, and high depression were more likely to smoke cigarettes, drink alcohol, and smoke marijuana than were their peers. Cigarette and alcohol use predicted marijuana use, which in turn predicted cocaine use.     

Paradoxical facilitation of attention in healthy humans

Transcranial magnetic stimulation (TMS)-induced virtual lesions in healthy subjects can be used to test neurofunctional models of disease. The interhemispheric rivalry model of heminglect is well suited for such investigations, as simple predictions derived from clinical data can be tested without the caveats normally associated with lesion studies. One of these predictions is that release from contralateral inhibition should lead to increased parietal responsiveness, which, in turn, would enhance spatial attention. Here, we detail studies showing TMS-induced paradoxical functional facilitation of attention in healthy individuals and highlight their contribution to the understanding and treatment of neglect syndromes.     

The Collaborative Longitudinal Personality Disorders Study (CLPS): overview and implications

The Collaborative Longitudinal Personality Disorders Study (CLPS; Gunderson et al., 2000) was developed to fill gaps in our understanding of the nature, course, and impact of personality disorders (PDs). Here, we review published findings to date, discuss their implications for current conceptualizations of PDs, and raise questions that warrant future consideration. We have found that PDs are more stable than major depressive disorder, but that meaningful improvements are possible and not uncommon. We have confirmed also that PDs constitute a significant public health problem, with respect to associated functional impairment, extensive treatment utilization, negative prognostic impact on major depressive disorder, and suicide risk. At the same time, we have demonstrated that dimensional models of PDs have clinical validity that categories do not, especially greater temporal stability. Furthermore, dimensional personality traits appear to be the foundation of behaviors described by many PD criteria. Taken together, our results lead us to hypothesize that PDs may be reconceptualized as hybrids of stable personality traits and intermittently expressed symptomatic behaviors.     

Dispositional and task-specific social-cognitive determinants of physical effort perseverance

The authors performed 3 studies to investigate the effects of social-cognitive variables on physical effort perseverance. Linear hierarchical regressions indicated that task-specific variables and perceived ability or competence accounted for the majority of perseverance variance in all 3 studies. The strongest single predictors in this cluster of variables were perceived competence, confidence, and readiness to invest effort. Physical self-health and ability accounted for a lesser portion of effort perseverance variance, with self-presentation confidence being the major single predictor in this cluster. The goal orientation cluster accounted for the least amount of effort perseverance variance. Together with task-specific confidence and the readiness to invest effort, as well as determination and commitment and competence, the findings support the contention that task-specific efficacious beliefs to a large extent determine persistence and endurance behaviors.