The use of mixed modeling to evaluate the impact of treatment integrity on learning

Treatment integrity, or the degree to which an intervention is implemented as intended, is a critical feature of skill acquisition tasks. Single‐case design consistently demonstrates that low treatment integrity slows or inhibits learning, but the relative impact of different types of instructional errors, or the presence of multiple errors, is less clear. The present study utilized a multilevel modeling approach to evaluate the impact of type of error (omission versus omission and commission) and error component (reinforcer delivery versus feedback) on learning. Findings revealed that learning outcomes worsened based on the type of error and as the complexity of errors increased; more specifically, participants performed better when only a single type of error occurred and when only a single error component was manipulated. Additionally, individual characteristics contributed to learning outcomes, highlighting the use of multilevel modeling as a helpful tool to supplement single‐case design. The differential impact of integrity errors on learning may be due to timing of errors (i.e., commission errors more likely to occur early in learning) or how errors affect reinforcement schedule versus discriminative control.     

Neurocognitive Effects of Methamphetamine: A Critical Review and Meta-analysis

This review provides a critical analysis of the central nervous system effects of acute and chronic methamphetamine (MA) use, which is linked to numerous adverse psychosocial, neuropsychiatric, and medical problems. A meta-analysis of the neuropsychological effects of MA abuse/dependence revealed broadly medium effect sizes, showing deficits in episodic memory, executive functions, information processing speed, motor skills, language, and visuoconstructional abilities. The neuropsychological deficits associated with MA abuse/dependence are interpreted with regard to their possible neural mechanisms, most notably MA-associated frontostriatal neurotoxicity. In addition, potential explanatory factors are considered, including demographics (e.g., gender), MA use characteristics (e.g., duration of abstinence), and the influence of common psychiatric (e.g., other substance-related disorders) and neuromedical (e.g., HIV infection) comorbidities. Finally, these findings are discussed with respect to their potential contribution to the clinical management of persons with MA abuse/dependence.     

The training & support programme for parents of children with ataxia: a pilot study

The aim of the study was to evaluate the impact of the Training and Support Programme among parents of children with ataxia. A total of 39 parents expressed an interest in the TSP, 27 (mean age 41; range 25-58) returned baseline questionnaires and completed the study. Twenty-four children (mean age 12.5 years, SD=12.4) received the TSP. Data were collected by self-administered questionnaires mailed to parents immediately before attending the TSP and at 4-month follow-up. Interviews were conducted with 10 parents immediately following TSP completion. Comparisons over time revealed significant decreases in parental anxious mood (p=.011), depressed mood (p=.046) and perceived stress (p=.020) and significant improvements in generalized self-efficacy (p=.010), satisfaction with life (p=.045) and parental health status (p=.020). Parents reported improvements in children's mobility, "jumping legs", sleep patterns, energy and activity levels, relaxation, and happiness (e.g., more smiles). Parents felt closer to their children and one parent had become "more accepting" of their child's ataxia. Results indicate that the TSP may enhance the psychosocial well-being of parents of children with ataxia although a randomized controlled trial would be necessary to determine whether the changes reported here are in fact due to attending the TSP.     

The effects of prohibiting gestures on children's lexical retrieval ability

Two alternative accounts have been proposed to explain the role of gestures in thinking and speaking. The Information Packaging Hypothesis (Kita, 2000) claims that gestures are important for the conceptual packaging of information before it is coded into a linguistic form for speech. The Lexical Retrieval Hypothesis (Rauscher, Krauss & Chen, 1996) sees gestures as functioning more at the level of speech production in helping the speaker to find the right words. The latter hypothesis has not been fully explored with children. In this study children were given a naming task under conditions that allowed and restricted gestures. Children named more words correctly and resolved more 'tip-of-the-tongue' states when allowed to gesture than when not, suggesting that gestures facilitate access to the lexicon in children and are important for speech production as well as conceptualization.     

The Theory of Planned Behavior Without Compatibility? Beyond Method Bias and Past Trivial Associations1

Overreliance on one measurement approach can challenge accurate statements about reality, as findings can represent by‐products of the compulsory measurement paradigm. Within the theory of planned behavior (TPB), the compatibility principle represents one such strictly imposed paradigm. Using 2 cross‐sectional surveys of 1,394 volunteers and involving structural equation models, we demonstrate that the widely employed practice of measuring TPB constructs is confounded with method‐implied bias. This means the theory cannot conclusively reveal origins of a behavior. Our results also suggest that on an aggregated level, when method bias is eliminated, its constructs are linked in hypothesized ways. Adopting a more general model—thus, adopting a more traitlike conceptualization of attitudes—has interesting implications for social psychology and its current trends.