Inference deficits in right brain-damaged patients

The inferential reasoning ability of right hemisphere-damaged (RHD) patients was tested by presenting pairs of sentences which were to be treated as single, integrated units. The two sentences treated together made one interpretation likely (a correct inference); one of the sentences in isolation encouraged a different interpretation (an incorrect inference). The position of the misleading sentence was systematically varied. Results showed that, in contrast to normal controls, RHD patients have more trouble answering inference questions, especially those concerning incorrect inferences, than answering questions about the factual content of the passages. Also, RHD patients made significantly more errors when the misleading information was contained in the first rather than in the second sentence; this finding indicates that these patients have difficulty revising previously acquired knowledge in light of new information. These results suggest the impairment of several components of normal discourse processing subsequent to right hemisphere brain damage.     

Testing mediating variables in a school-based nutrition intervention program.

This study identified mediators of a school-based nutrition intervention for 4th graders and their parents. Nine variables were tested for satisfying 4 conclusions necessary to establish mediation of intervention effects on changes in fruit and vegetable consumption (FVC) in 4th graders (N = 1,676). FVC was measured in children by the use of 24-hr dietary recalls. Mediators were assessed by the use of questionnaires completed by children and parents. All 4 conclusions were met for positive outcome expectancies. Knowledge, self-efficacy, and parent consumption satisfied the first 3 conclusions for mediation but the mediating effects were not statistically significant (Conclusion 4). Future mediational analyses and the creation of a national database of mediators are crucial for increasing strength and efficiency of school-based nutrition programs.     

Mediation of a middle school skin cancer prevention program.

This study tested potential mediators of a school-based skin cancer prevention intervention for middle school children (6th-8th grades; N = 1,788). Ten variables were tested on 4 criteria to establish mediation, including (a) intervention related to outcome, (b) intervention related to mediators, (c) mediators related to outcome, and (d) mediated effect statistically significant. Sun-safe behaviors (e.g., sunscreen use) and potential mediators were measured with a self-report questionnaire. All criteria were met for Barriers--Sunscreen, Perceived Self-Efficacy, and Knowledge when the mediators were tested separately. In multiple mediator analyses, barriers to sunscreen use and self-efficacy satisfied Criteria 1-3 but were not statistically significant (Criterion 4). Barriers to sunscreen use, perceived self-efficacy for sun-safe behavior, and knowledge may serve as mediators.