The semantics ofR4

The LogicR4 is obtained by adding the axiom (A vB(AvB) to the modal relevant logicNR. We produce a model theory for this logic and show completeness. We also show that there is a natural embedding of a Kripke model forS4 in eachR4 model structure.We are indebted to several people for discussions relating to the topic of this paper, in particular, Kit Fine, John Slaney, J. M. Dunn, Jacques Riche, M. A. McRobbie, and Jill LeBlanc. We would also like to thank the Automated Reasoning Project for material assistance. Mares would like to thank The Social Sciences and Humanities Research Council of Canada for fellowships 456-89-0128 and 457-90-0081, which supported him while writing this paper.     

Schedule-induced defecation by rats during ratio and interval schedules of food reinforcement.

Lever pressing in rats was maintained by continuous and intermittent schedules of food while defecation was monitored. In Experiment 1, reinforcement densities were matched across variable-ratio and variable-interval schedules for three pairs of rats. Defecation occurred in all 3 rats on the variable-ratio schedule and in all 3 rats on the yoked variable-interval schedule. In Experiment 2, fixed-ratio and fixed-interval schedules with similar reinforcement densities maintained lever pressing. Defecation occurred in 3 of 4 rats on the fixed-ratio schedule and in 4 of 4 rats on the fixed-interval schedule. Almost no defecation occurred during continuous reinforcement in either experiment. These results demonstrate that defecation may occur during both ratio and interval schedules and that the inter-reinforcement interval is more important than the behavioral requirements of the schedule in generating schedule-induced defecation.     

Frequency ratios and the discrimination of pure tone sequences

We examined the effect of frequency ratios on the discrimination of patterns of alternating pure tones (ABABA). Listeners heard a repeating pattern presented in transposition (same frequency ratios between successive tones, different absolute frequencies) and were required to indicate when the pattern changed (different frequency ratios and absolute frequencies). Changes from patterns with simple frequency ratios to those with more complex ratios were more readily detected than were changes from complex ratios to simpler ratios.     

Antidepressant Medication: Is It a Viable and Valuable Adjunct to Cognitive-Behavioral Therapy for School Refusal?

Cognitive-behavioral therapy (CBT) is an evidence-based treatment for school refusal. However, some youth do not respond to CBT. The serious risks associated with school nonattendance call for novel approaches to help those who do not respond to CBT. Because school refusal is commonly associated with anxiety disorders, and the combination of CBT and antidepressant medication enhances outcomes in the treatment of anxiety disorders, combined treatment may be effective for school refusal. This narrative review evaluates the current evidence base for adding antidepressant treatment to CBT for school refusal. Six randomized controlled trials (RCTs), two open trials, six case studies/series, and one observational study were identified and reviewed. There is support for combined CBT and imipramine, but this medication is not typically used due to the risk of concerning side effects. Two recent RCTs failed to provide evidence for the superiority of combined CBT and fluoxetine. Further research in this area is required because the extant studies have a number of methodological limitations. Recommendations are provided for clinicians who consider prescribing antidepressant medication or referring for adjunctive antidepressant treatment for school refusal.     

The effects of listener training on the development of analogical reasoning

We evaluated the effects of listener training on the emergence of analogical reasoning, as measured via equivalence‐equivalence and explored the role of verbal behavior when solving analogy‐type tasks. We taught 18 college students to select component stimuli from 2 classes, labeled “vek” and “zog,” and evaluated tacts and relational responding in the presence of baseline (AB and BC), symmetry (BA and CB), and transitivity (AC and CA) compounds. In Experiment 1, 5 out of 6 participants passed analogy tests, but none of them engaged in the relational tacts “same” and “different” during tact tests, possibly due to lack of instructional control. A change in instructions during Experiment 2 produced relational tacts in 4 of 6 participants, and 5 participants passed analogy tests. In Experiment 3, we implemented a talk‐aloud procedure to determine if the participants were emitting relational tacts during analogy tests. All 6 participants tacted stimuli relationally and engaged in problem‐solving statements to solve analogy tests. Results from these studies suggest that listener and speaker behavior in the form of relational tacts and other problem‐solving statements influenced the participants' equivalence–equivalence performance.     

Teaching minority high school students to recruit helpers to attain personal and educational goals

Recruiting help from mentors and other potential helpers is a promising strategy for helping disadvantaged and minority youths meet their personal and educational goals. Three African-American high school seniors participated in a project designed to evaluate the effectiveness of training procedures that would allow them to ask for help in attaining educational and other personal goals. A behavioral training procedure that included instructional materials, role-play practice, praise, and feedback was used. Targeted skills included goal setting and 30 responses involved in the process of meeting with a potential helper. Role-play situations were used to evaluate participants' help-recruiting skills before and after training. Participants increased their help-recruiting skills from an average of 38% during baseline, to an average of 75% after training. Self-reported measures of goal attainment suggested that the students benefited from the training. Implications for mentoring programs designed to increase minority students' opportunities to reach educational goals were discussed.