Orientation in cognitive maps

In 14 experiments, subjects had to “point to” surrounding environmental locations (targets) while imagining themselves in a particular spot facing in various directions (orientations). The spatial information was either committed to memory (cognitive maps) or directly presented on each trial in the visual or tactile modality. Reaction times (RT) indicated that orientation shifts were achieved through mental rotation in the visual task, but not in the cognitive map or tactile tasks. Further, in the latter two tasks targets were located most quickly when they were adjacent to or opposite the imagined orientation. Several explanations of this finding were tested. Various aspects of the data suggest that cognitive maps are not strictly holistic, but consist of orientation-specific representations, and—at least in part—of relational propositions specific to object pairs.     

Hemiplegic writing in severe aphasia

Three patients with severe aphasia and right hemiplegia are described who could write to dictation with the right arm using a limb prosthesis though agraphic with the "intact" left hand. The phenomenon of "hemiplegic writing" is explained as an access to submerged or preprocessing levels in language and action structure, through the use of older proximal motor systems. This interpretation has implications for our understanding of language and brain function, as well as for approaches to the treatment of patients with severe language disorders.     

A quasi-experimental investigation of message appeal variations on organ donor registration rates.

OBJECTIVE: Approximately 6,000 Americans die every year awaiting an organ transplant. Health promotion interventions may alleviate the shortage of viable organs by increasing the number of registered organ donors. This study is the first to evaluate the differential effectiveness of various organ donor messages in naturalistic settings. DESIGN: A 4 (Appeal)x4 (Exemplar)x4 (Location) counterbalanced quasi-experimental design was implemented. MAIN OUTCOME MEASURE: The behavioral outcome measure was the number of individuals who registered to be organ donors at computer kiosks. RESULTS: A number of significant main effects and interactions emerged. Most notably, of the 4 different appeals (counterargument, emotional, motivating action, dissonance), counterargument was by far the most efficacious, especially in academic-type settings (library, university, community college); the emotional appeal was most successful in hospitals. CONCLUSIONS: The findings from this study have implications for both organ donor investigations and health campaign research in general. Statistical interactions highlight the importance of evaluating multiple exemplars in multiple locations for each type of appeal when conducting health campaign research.     

Improving Delivery Behaviors During Exposure for Pediatric OCD: A Multiple Baseline Training Trial With Community Therapists

This study tested whether a new training tool, the Exposure Guide (EG), improved in-session therapist behaviors (i.e., indicators of quality) that have been associated with youth outcomes in prior clinical trials of exposure therapy. Six therapists at a community mental health agency (CMHA) provided exposure therapy for 8 youth with obsessive–compulsive disorder (OCD). Using a nonconcurrent multiple baseline design with random assignment to baseline lengths of 6 to 16 weeks, therapists received gold-standard exposure therapy training with weekly consultation (baseline phase) followed by addition of EG training and feedback (intervention phase). The primary outcome was therapist behavior during in-session exposures, observed weekly using a validated coding system. Therapist behavior was evaluated in relation to a priori benchmarks derived from clinical trials. Additional outcomes included training feasibility/acceptability, therapist response to case vignettes and beliefs about exposure, and independent evaluator-rated clinical outcomes. Three therapists reached behavior benchmarks only during the EG (intervention) phase. Two therapists met benchmarks during the baseline phase; one of these subsequently moved away from benchmarks but met them again after starting the EG phase. Across all therapists, the percentage of weeks meeting benchmarks was significantly higher during the EG phase (86.4%) vs. the baseline phase (53.2%). Youth participants experienced significant improvement in OCD symptoms and global illness severity from pre- to posttreatment. Results provide initial evidence that adding the EG to gold-standard training can change in-session therapist behaviors in a CMHA setting.     

Comparing computer‐based training and lecture formats to teach visual analysis of baseline‐treatment graphs

Accurate analysis of data is vital to the validation of interventions. As such, there has been a recent increase in studies evaluating visual analysis training procedures. However, past investigations have not evaluated direct and indirect visual analysis training methods with matched instructional content that was systematically designed. Furthermore, training has rarely included assessment of generalization and maintenance of visual analysis skills. The purpose of the current dissertation study was to compare the effectiveness and efficiency of (a) computer‐based training, (b) lecture formats with and (c) without the opportunity to pause, and (d) a no‐training group to teach visual analysis of AB graphs to university students. To make these formats directly comparable, the instructional content was equated by ensuring information and examples were identical across the three training procedures. Eighty‐three students were randomly assigned to one of the four groups. Results showed that all three training formats produced increases in accurate responding compared to the no‐training group. Visual analysis skills generalized to novel graphs and maintained approximately 2 weeks following all trainings. These results suggest that structured approaches that are carefully designed to train visual analysis are effective and lead to gains that generalize and maintain in the absence of training.     

The danger of conflating level-specific effects of control variables when primary interest lies in level-2 effects

In the multilevel modelling literature, methodologists widely acknowledge that a level-1 variable can have distinct within-cluster and between-cluster effects, and that failing to disaggregate these can yield a slope estimate that is an uninterpretable, conflated blend of the two. Methodologists have stated, however, that including conflated slopes of level-1 variables in a model is not problematic if substantive interest lies only in effects of level-2 predictors. Researchers commonly follow this advice and use methods that do not disaggregate effects of level-1 control variables (e.g., grand mean centering) when examining effects of level-2 predictors. The primary purpose of this paper is to show that this is a dangerous practice. When level-specific effects of level-1 variables differ, failing to disaggregate them can severely bias estimation of level-2 predictor slopes. We show mathematically why this is the case and highlight factors that can exacerbate such bias. We corroborate these findings with simulations and present an empirical example, showing how such distortions can severely alter substantive conclusions. We ultimately recommend that simply including the cluster mean of the level-1 variable as a control will alleviate the problem.